INTERNATIONAL HYDROGRAPHIC REVIEW
MAY 2014
THE
INTERNATIONAL
HYDROGRAPHIC
REVIEW
INTERNATIONAL HYDROGRAPHIC ORGANIZATION
MONACO
Publication P-1
No. 11
MAY 2014
INTERNATIONAL HYDROGRAPHIC REVIEW
MAY 2014
© Copyright International Hydrographic Organization [2014]
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INTERNATIONAL HYDROGRAPHIC REVIEW
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□ Editorial
By Ian HALLS, Editor
5
□ Articles
- No Solace from SOLAS.
7
by : Ian RUSSEL (UK)
- Next generation paper chart.
21
by : Ian HALLS (Australia)
- Research on the design of survey lines in a marine
31
magnetic survey
by : Gang BIAN (China)
Wei XIA (China)
Shaohua JIN (China)
Fumin XIAO (China)
Xinxuan SUN (China)
Yang CUI (China)
□ Notes
- The AGS 61 “CABO DE HORNOS” New Chilean Scientific
Research Vessel.
49
by : Captain Fernando MINGRAM (Chile)
- IC-ENC ENC Validation Training Course.
by : Laura TYZACK (Greece)
Panagiotis GKIONIS (Greece)
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Editorial
This edition comprises three Articles and two Notes.
The first Article discusses the need for continued survey and charting in key oceanic
areas. Despite all the modern technology available, mishaps at sea continue to occur.
As ships become larger in size and venture further away from regularly surveyed
routes, there is a constant need for hydrographic agencies to provide hydrographic
services, capability and up-to-date, comprehensive nautical products. The paper
identifies a number of key issues regarding navigation safety and the associated risks.
The author also provides examples of technologies to help fill data gaps and
describes some risk assessment initiatives being undertaken to prioritise activities.
The second Article is penned by myself. The Australian Hydrographic Office (AHO) is
currently updating its information management and production systems. Having
recently achieved full ENC coverage of its waters, the AHO is stepping out and
actively encouraging nautical chart users to adopt ENCs for navigation. The AHO will
cease production of its Raster Navigation Chart (RNC) in July 2014 bringing to a close
an interim electronic charting solution introduced in the early 2000’s. As the uptake of
ENCs continues, together with the challenge of supporting paper nautical chart and
ENC production and distribution, I have raised the question regarding multiple data
portrayals for charting products and the possibility to create a new paper chart product
that is derived from the ENC data with a predominant S-52 (ECDIS) portrayal as well
as possible plotting options – HO and user.
Our third Article outlines a method to improve the precision and efficiency of marine
magnetic surveys. Using detailed simulations, the authors identify evaluation methods
using magnetic anomaly maps the interpolation precision between survey lines to
assist in determining optimal survey line configuration.
The first of the two Notes provides the rationale for the Chilean Navy to purchase a
new scientific research vessel. The Note provides a brief history of the marine
research programme and a description of the vessel along with examples of survey
and oceanographic expeditions to test the vessel’s capability.
The second Note reviews the latest ENC validation training course established by
IC-ENC and provides real-world examples of issues with ENC encoding inconsistencies. The paper describes the role IC-ENC and the close relationship with HOs to
rectify the issues. Australia has a local IC-ENC presence and I support this training
initiative. This is a valuable resource that IC-ENC provide in improving ENC data quality and identifying issues with adjoining ENCs produced by other Nations. This course
would be very useful for HO ENC production staff to undertake.
On behalf of the Editorial Board, I hope that this edition is of interest to you. Thank you
to the authors for your contributions and to my colleagues who provided peer reviews
for the articles in this edition.
Ian W. Halls
Editor
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NO SOLACE FROM SOLAS
The Effects that Deeper Draughts
and the ENC are having on Safe Navigation
By Ian RUSSELL (FRICS, MNI - UK)
Abstract
Chapter V Regulation 9 of the SOLAS Convention, annexed for reference, requires
contracting governments to provide hydrographic services. Many signatories cannot
provide these unaided. This is despite the fact that new cruise ship itineraries and trade
routes are being established in their waters for increasingly larger and deeper draught
vessels. This article reviews a number of chart related casualties. These demonstrate that
no chart, paper or digital, is infallible. This emphasizes the urgent need for new and better
hydrographic data collection in some key oceanic areas. Potential innovative solutions for
data acquisition and hydrographic capacity building strategies are considered.
Résumé
La règle 9 du chapitre V de la convention pour la sauvegarde de la vie humaine en mer
(SOLAS), annexée à titre de référence, impose aux gouvernements contractants de fournir
des services hydrographiques. Un grand nombre de signataires ne peuvent fournir ces
services sans aide. Et ce, en dépit du fait que de nouvelles routes commerciales et de
nouveaux itinéraires pour les navires de croisière soient adoptées dans leurs eaux pour
des navires de plus en plus grands et aux tirants d’eau de plus en plus importants. Cet
article examine un certain nombre de pertes liées aux cartes marines. Ces dernières
illustrent le fait qu’aucune carte, papier ou numérique, n’est infaillible. Ceci souligne le
besoin urgent de recueillir des nouvelles données hydrographiques de meilleure qualité
dans certaines zones océaniques clés. Des solutions potentiellement innovantes pour
l’acquisition des données et des stratégies de renforcement des capacités hydrographiques
sont examinées.
Resumen
El Capítulo V de la Regla 9 de la Convención SOLAS, que se adjunta como referencia,
requiere que los gobiernos contratantes proporcionen servicios hidrográficos. Muchos
signatarios se ven ante la imposibilidad de proporcionar dichos servicios sin ayuda. Esto
sucede a pesar del hecho que se están estableciendo nuevos itinerarios para los buques
de cruceros y que se están estableciendo rutas comerciales en sus aguas para buques
cada vez mayores y de calado más profundo. Este artículo examina un número de
accidentes desafortunados relacionados con las cartas. Estos demuestran que ninguna
carta, ya sea de papel o digital, es infalible. Lo anterior destaca la urgente necesidad de
contar con una colección de datos hidrográficos nueva y mejor en algunas zonas oceánicas clave. Se consideran posibles soluciones innovadoras para la adquisición de datos y
para nuevas estrategias de creación de capacidades hidrográficas.
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INTERNATIONAL HYDROGRAPHIC REVIEW
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the related IMO and IHO committees and working
groups supports the contention that the presentation of ENC in ECDIS is capable of improvement.
The evolution of ENC from the paper chart has
resulted in the former inheriting the limitations of
the latter. In the critical matter of enabling the user
to assess the quality of bathymetric data, the ENC
is frequently inferior to its predecessor.
Introduction

ENC Data Portrayal Issues
The phased introduction of the mandatory Safety
of Life at Sea (SOLAS) Convention Electronic
Chart Display and Information System (ECDIS)
carriage requirement, predicated the IHO Member
States’ commitment to full Electronic Navigational
Chart (ENC) coverage. This poses the question
whether the status of hydrographic survey and
charting worldwide and the quality of hydrographic
data is adequate to support the emerging
technology. This is a concern, given the aspiration
of the International Maritime Organisation (IMO) to
implement the e-Navigation concept within the
current decade.

Status of Hydrographic Surveys
Table 1 indicates the extent of the data acquisition
task facing even established hydrographic authorities, if they are to meet the perceived demands on
their products. It also draws attention to the need
for those developing States, parties to the SOLAS
Convention Chapter V Regulation 9 (SOLAS V/9),
to meet their obligations for the provision of hydrographic services. A significant number of coastal
and Island States have signed up to SOLAS
V/9 with no means of implementing it. This has
produced a new and critical situation with regard to
safe navigation.
It raises a number of questions for chart producers
and users alike. The chart catalogues of International Hydrographic Organisation (IHO) Member
States reveal that, away from the main traffic
routes and major port approaches, ENC must have
been compiled from charts of limited utility for the
needs of contemporary shipping. This is compounded by the unsatisfactory portrayal of data
quality in ECDIS. In many cases ENC producers
have resorted to use of the “Unassessed” symbol
for this critical attribute.
Under this regulation, which came into effect in
2002, contracting governments undertake to execute hydrographic surveys, prepare, issue and
update nautical charts and publications and ensure
uniformity in their products and world-wide availability. These obligations must be based on the
appropriate resolutions and recommendations of
the IHO.
A review of the literature and the proceedings of
Table 1. Examples of the status of Hydrographic Surveys 2013 (source: IHO C-55)
Region
SW Pacific
Polar regions
Unsurveyed
or requires better data
(0-200m deep)
>95%
>95%
Caribbean
>80%
W. Africa
>80%
E. Africa
>76%
Includes Somalia
W. Indian Ocean
>73%
Excludes Maldives
Papua New Guinea
>72%
Australia
>65%
Greece
>65%
USA
>40%
UK
>30%
France
>19%
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Remarks
INTERNATIONAL HYDROGRAPHIC REVIEW
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The projected increase in commodity shipments to
and from the emerging economies and the continuing search for and exploitation of new mineral deposits is having similar consequences elsewhere
e.g. Indonesia, Papua New Guinea and the South
China Sea. Significantly there is no information
available on the status of hydrographic surveying
in Indonesia or the disputed Paracel and Spratly
Islands in the South China Sea.
The International Hydrographic Bureau (IHB), as
the Secretariat of the IHO, provides guidance,
advice and support in all hydrographic areas, in
particular to those countries interested in establishing or expanding their hydrographic capabilities in
order to fully satisfy the obligations of the new
regulation. The IHO Capacity Building Strategy
policy document was published in 2006 to provide
guidance on the implementation of this remit. The
strategy is currently under review as discussed
later.
An example of some of the work needed elsewhere, is that for updating the 1970’s single beam
echo sounder surveys of the Malacca Strait. This
has been requested by the International Chamber
of Shipping (ICS). It would significantly enhance
the utility of the proposed Malacca and Singapore
Straits Marine Electronic Highway. Commercial
survey companies have the capacity to undertake
the work if funding is forthcoming.
The advent of deeper draught shipping has increased the urgency for national programmes to
review and upgrade coverage based on surveys
carried out before the development of sidescan
sonar and multi-beam echo sounder (MBES). The
increasing tendency of cruise liners to seek new
routes, anchorages, and port calls, has highlighted the need for more rigorous survey of areas
which were originally explored in the nineteenth
century. This is a major challenge for developing
hydrographic services in the Caribbean, Indian
Ocean and SW Pacific areas.
Deeper Ships Dangerous Seas
Table 2 shows the progressive increase in the size
of vessels.
Table 2. Progressive increase in the size of vessels. The dimensions of those now at sea and on order, reflect
the shipping industry’s response to changing operational and trading patterns.
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Contemporary vessel draughts have dictated the
survey and charting requirements and the depth
criteria for the definition of a dangerous wreck. For
UKHO this is currently 28m (15 fathoms). Until
1960 it was only 14.6m (8 fathoms).
draught 8m), recently converted into a cruise ship,
on passage from La Guaria in Venezuela to Barbados, struck an uncharted reef half a mile off the
NW coast of Mustique in the passage which
separates that island from Baliceaux in the
Grenadine Islands. As the ship proceeded at a
speed of 16 knots, the impact caused her to break
in two, catch fire and become a total loss.
Despite a steady increase in the length of cruise
ships the draught of the current vessels in service
has not increased proportionately and averages
8.4m. The increased length will mean that unless
host ports can expand and deepen berthing areas
and approach channels, more attention will need to
be given to surveying roadstead anchorages. An
example of the work required is shown in Figure 1.
The passage being attempted was through apparently open water, with charted depths of 13 and 16
metres some 3½ cables (640m) wide, between two
rock outcrops, in a coral and reef-strewn area last
surveyed in the 19th century. This followed an
alteration to the planned voyage. It was authorised
by the master in order, as the subsequent legal
proceedings revealed, 'to provide his passengers
with a better look at this enchanting isle’ and was
consistent with his desire to implement the
Owner's policy of making Antilles' cruises entertaining and unique.
Two decades later another ocean liner undertaking
a cruise provided a further example of the danger
involved in such a vessel operating in inshore waters. In August 1992, Queen Elizabeth 2 (l.o.a.
294m ((63 ft), beam 32m (105 ft), draught 9.85m
(32 ft)) grounded on uncharted and previously unsurveyed rocks to the south of Cuttyhunk Island,
off the east coast of the USA. She was then on
passage from Martha's Vineyard to New York. In
trying to make up time for an ETA at her next port
of call, speed was increased to about 25 knots.
This was not warranted by the general depth of
water and induced 4 feet of squat. Consequently
the vessel grounded on rocks which a subsequent
survey found to have a least depth of 33 and 34
feet. The charted least depth in the vicinity was 39
feet; this was confirmed by the re-survey. The nature of the seabed was shown as rock.
Figure 1. Antigua 2011 - Full seafloor coverage of
St John’s Harbour and St John’s Roads (last surveyed in
1849)
Source UKHO [1] presentation to Meso-American and
Caribbean Hydrographic Commission.
Extract from Admiralty Chart 2065 © Crown Copyright and/or
database rights. Reproduced by permission of the Controller of
Her Majesty’s Stationery Office and the UK Hydrographic Office
(www.ukho.gov.uk)
The owners of the QE2 sued the USA for
negligence on the part of the charting authority for
failing to carry out a more thorough hydrographic
survey of the area. In particular, they claimed that
the 39 foot sounding had not been examined. The
charting authority stated that there was no reason
to develop the 39 foot sounding further because it
was outside the normal shipping lanes and that in
1939, when the area had last been surveyed, large
vessels such as the QE2 never frequented those
waters. The court accepted this argument and
dismissed the claim.
Cruise ships are now venturing into increasingly
remote and poorly charted areas such as the Polar
Regions, SW Pacific, Indian Ocean and the Caribbean. Itineraries that seek to provide optimum
passenger experience could have unintended
consequences.

Cruise Ship Crashes
In April 2000, the “Adventure” cruise ship World
Discoverer (l.o.a. 87m, beam 15m, draught 4.57m)
grounded on a large allegedly uncharted rock or
An example of what such ventures may lead to
occurred in January 1971 when the French passenger liner Antilles (l.o.a.183m, beam 24.4m and
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the coast of the bay, which does not seem to have
been charted. However, jetties with vessels alongside and a large ship offshore can be seen on
Google Earth. As can what appear to be open cast
mineral workings.
reef in Sandfly Passage, Solomon Islands. The
ship was fatally holed and the master beached her
in Roderick Dhow Bay, where the hulk remains.
Early in 2012 the Indonesian Navy Hydrographic
Service (DISHIDROS) carried out a single beam
Figure 2. Portion of chart BA 1713 current at the time
of the grounding showing the shoals in the northern
entrance to Sandfly passage, on which it is presumed
World Discover struck and her final resting place in
Roderick Dhu Bay. [2].
Extract from Admiralty Chart 1713 © Crown Copyright and/or
database rights. Reproduced by permission of the Controller
of Her Majesty’s Stationery Office and the UK Hydrographic
Office (www.ukho.gov.uk)
Figure 3. Sketch map derived from Chart BA 2788
showing position of grounding in relation to Noble
Hawk’s departure point, adjacent depths and shoal
areas.
Neither the Australian Hydrographic Service nor
the UK Hydrographic Office, the Primary Charting
Authority, has any record of the incident. The
stranded wreck of World Discover is clearly visible
on Google Earth, but is not shown on the latest
(2012) edition of chart BA 1713. The Pacific Island
Pilot, current at the date of the incident, advises
that; “Deep-draught vessels should not attempt the
passage owing to the reefs in the N entrance.” The
latest (2007) edition of the Pilot directs vessels
west of Mid Reef; passing clear of the 9.1m patch.
This remains the least depth shown in the passage
other than the reef itself.

and sidescan sonar survey of the grounding site
and found a least depth of 3m (10 feet) and an
adjacent depth of 15.3m (8fm 2 feet) in general
depths of 50m (27fms). Mindful of the significant
activity of large cruise ships and bulk carriers in
these waters, DISHIDROS recommended the
installation of a navigation beacon on the feature. It
is uncertain whether or not this recommendation
has yet been acted upon.

Oceanic Dangers
The significant draughts in the Table 2 are those of
the large cargo vessels which now exceed 17m
and are as much as 24.5m. New Panamax vessels
transiting the Caribbean may not be able to do so
with the same confidence as their predecessors.
Elsewhere ULCC and large bulk carriers are
vulnerable to an encounter with an uncharted
seamount rising close to the surface. In the deep
areas of the ocean, most mariners consider that
there is little chance of such a mishap. Unfortunately, this is a misconception.
Uncharted Rock
Such dangers also exist for large cargo vessels
navigating in poorly charted waters to service the
exploitation of newly-found mineral resources. A
prime example occurred in late 2010. The bulk
carrier Noble Hawk (l.o.a.190m (623 ft), beam 33m
(108 ft), draught 12.5m (41 ft)), starting a passage
to China from Pulau Mabuli on Halmahera Island in
Eastern Indonesia, grounded on an uncharted 5m
(16 ft) shoal. The surrounding depths were 29 to
32 fms (53 to 58m). Her course lay across Teluk
Buli which is much encumbered with islets, reefs
and shoals. She was loaded with nickel ore
embarked from a berthing facility somewhere on
In 1973 the cargo ship Muirfield, with a draught of
16m, was on passage from the Cape of Good
Hope to Selat Sunda. There was a 2-3m swell
running when she struck the top of a seamount, 75
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miles south west of the Cocos Islands. A subsequent survey showed this to be half a mile in
extent; with a least depth of 18m in charted depths
of over 5,000 metres. Two further examples of
navigationally significant seamounts, discovered in
the South Atlantic and Indian Ocean, include Vema
Seamount (with a charted depth of 11 metres about 1,000 km west-north-west of Cape Town)
and Walters Shoal Seamount (with a charted depth
of 15 metres - about 400 nautical miles south of
Madagascar). These seamounts rise up from
ocean depths of about 4,000 and 2,000 metres
respectively.
In June 1970 a fleet auxiliary vessel of the Royal
Navy, the tanker Ennerdale, (l.o.a. 744 ft (227m),
beam 98 ft (30m), draught 40 ft (12m)) struck a
rock pinnacle about 8 miles NNE of Port Victoria in
the Seychelles. This opened up her starboard
side, causing her to heel over and settle on the
seabed. The pinnacle, which was charted at 9fms
(16.5m), lay adjacent to a 10fm sounding in general depths of 13 to 16fms. The vessel, travelling
at 12kts, was crossing a line of pinnacles and islet
outcrops which extend north eastwards from the
north tip of the Island of Mahé within the 20 fathom
line.
More than 90% of all seamounts greater than 1km
in height (estimated to be more than100,000) are
unobserved by either ship soundings or satellite
gravity [3]. This observation is consistent with the
statement in IHO publication C-55 that renewed
attention needs to be given to the disproving of
vigias especially adjacent to the maritime shipping
routes in the Pacific and adjacent seas. The danger to submarine navigation is self evident. This is
exemplified by the incident involving a nuclear
powered submarine of the US Pacific fleet that
collided with a seamount about 364 nautical miles
southeast of Guam.
The chart in use was compiled from a 19th century
(lead line) survey, as clearly stated in the title
block. Considering this fact the least depth of water
over the pinnacle (subsequently established at
10.8m (35ft)) may well not have been shown on
the chart in use. However, there was sufficient
indication on the chart that shoaler water may well
have existed in the vicinity. The prime cause of the
accident, leading to a total loss of the vessel, was
poor execution of the navigational departure plan,
which would otherwise have taken the vessel clear
of the danger.
A far more recent incident took place in January
2013, when a mine counter-measures vessel USS
Guardian (l.o.a. 68m (224 ft), beam 12m (39 ft),
draught 4m (13 ft)) ran aground on Tubbataha reef
in the Sulu Sea. On the coastal scale Digital
Nautical Chart (DNC) being used the reef was
positioned 8 miles to the east of its correct
position, in contradiction to the general scale DNC
and the standard paper chart. Unfortunately, the
approved voyage plan in the Voyage Management
System used the coastal DNC and no attempt was
made to investigate the discrepancy. This decision
was based on the supposition that it was well
known 'that general charts are inaccurate', a
remark which, aided by the bridge team's preference to rely on the DNC rather than to take corrective action when a light on the reef was raised,
resulted in the total loss of the ship.
The submarine was travelling at maximum speed
at a depth of 525 feet (160 m). The seamount that
she struck did not appear on the chart in use at the
time of the accident. Other charts available for use
showed an area of "discoloured water", an indication of the probable presence of a seamount. The
US Navy investigation [4] determined that information regarding the seamount should have been
transferred to the charts in use; particularly given
the relatively uncharted nature of the ocean area
that was being transited and that the failure to do
so represented a failure to follow proper procedures. Fortunately the pressure hull was not
breached enabling the submarine to surface and
be escorted to Guam for temporary repairs.

Caveat Navigator
This submarine accident is indicative of the fact
that the failure to make proper use of limited
charted information, whether on paper or a screen,
applies as much to the bridge personnel of naval
vessels as to those of commercial vessels. The
unsatisfactory portrayal of the reliability of charted
information in ECDIS means even more caution
needs to be currently exercised by mariners when
away from regular routes. Two further examples,
although separated by more than 40 years, are
pertinent to this general discussion.
The focus for future survey effort:
some examples

Traffic Routing
Traffic surveys using the satellite Automatic Identification System (AIS) can provide preliminary
indications of where future data acquisition effort
might need to focus. This can be augmented in
consultation with the IMO and representative
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INTERNATIONAL HYDROGRAPHIC REVIEW
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industry bodies such as, the International Chamber
of Shipping (ICS), the International Association of
Independent Tanker Owners (INTERTANKO), the
International
Association
of
Dry
Cargo
(INTERCARGO), and the Baltic and International
Maritime Council (BIMCO).
C-55 notes that the banks and vigias near
Coetivy Island (Seychelles) lie on the flanks of a
trans-ocean sea-lane and require thorough
examination. This route is used by ships transiting
the Mozambique Channel and turning eastward
north of Madagascar. Similarly surveys are
required south of Mauritius as ships divert
eastwards from the shortest route to the Gulf to
avoid pirates as evident from Figure 5.
Figure 5. Satellite AIS data in the WIO Marine
Highway Development area
Image from presentation by South African Marine Safety
Agency (SAMSA) on the results of the Global Environmental Facility (GEF) - Western Indian Ocean Marine Highway Development and Coastal and Marine Contamination
Prevention Project.
The French Hydrographic Service (SHOM)
completed a route survey in the Mozambique
Channel in 2010 for the Western Indian Ocean
(WIO) Marine Highway. SHOM is deploying a
survey vessel to the Indian Ocean again in 2014
and there is mention of a survey en-route of a
possible gap (unspecified) in the Highway. Recent
(2012) Satellite AIS data (refer Figure 5) clearly
shows where survey priorities should lie. Even
though the situation in the Mozambique Channel is
probably understated as vessels frequently turn off
their AIS to avoid revealing their position to pirates.
Figure 4. Ship traffic in the vicinity of Jomard
Entrance, Papua New Guinea
Taken from NAV 59/INF.3 31 May 2013 [5]
Extract of Chart Aus 4621 Copyright Commonwealth of
Australia (2011). Used with permission of the Australian
Hydrographic Service.
In Figure 4, AIS data marks the route through
Papua New Guinea waters from Eastern Australian
to Asian ports and substantiates the assessment
that:
Ships diverting south of Mauritius now pass closer
to that island to embark or disembark security
personnel. The pattern of risk to the region’s
ecosystems has therefore changed, increasing the
exposure of the south coast of Madagascar,
Mauritius, Rodrigues and the Maldives.
Papua New Guinea is experiencing a marked
increase in the volume of international ship traffic
through its waters. It is estimated that some 7,360
ships transited its waters in 2012. The majority of
this traffic was to and from ports on the eastern
seaboard of Australia. There are growing risks to
the safety of navigation and protection of the
sensitive marine environment associated with this
increasing traffic. Areas of particular concern are
Jomard Entrance and the area east of Rossel
Island. However, the quality (Zone of Confidence
or ZOC) of the hydrographic surveys in the
Jomard Entrance area is category "C". Therefore,
it would be necessary to improve hydrographic
information available for the area, before any ship
routeing systems are established.
In hindsight the route survey in the Mozambique
Channel was perhaps not the best use of limited
deep water multibeam survey resources. The WIO
Marine Highway Development (MHD) project
participants’ proposal to establish a new recommended route for all ships in the Mozambique
Channel was rejected by IMO Member Sates. The
route would have been approximately 1,000 miles
long. The compelling need for the measure was
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INTERNATIONAL HYDROGRAPHIC REVIEW
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unclear. No statistical evidence had been provided
regarding shipping casualties or near misses. This
omission made it very difficult to quantify the anticipated benefit that the proposal might have
delivered. The route would have needlessly denied
the full use of a wide deep water channel. It was
felt that concentrating shipping into restricted lanes
could potentially have increased the risk of
collision.
at all, while alarming, are perhaps unrepresentative of the practical situation. Rather what is
needed is a figure for that portion of useable sea
space suitable for shipping that is in urgent need of
survey. As a starting point one might refer to the
routes in UKHO’s NP136 (Ocean Passages for the
World). An example of which is given in Figure 6.
Details of current and potential cruise ship destinations can be sought from operators. Analysis is
required of the likely demands for updated charts
to support emerging new trading patterns. These
will be associated with developing exploitation and
shipment of mineral resources and hydro carbons
and with consumer demand and export growth in
the emerging economies of this decade and
beyond.
The refusal of the IMO to designate a recommended route through the Mozambique Channel
could have unintended consequences for any future international effort to focus survey effort on
routes rather than the traditional area surveys. Although the Mozambique Channel was not
a typical case, the World Bank’s assessment [6] of
the WIO MHD project found that ‘the relevance of
the marine highway concept to increase the safety
and efficiency of navigation in the Mozambique
Channel is questionable’ and that ‘The Mozambique Channel is not appropriate for such a
scheme for two reasons: it is wide (400 km wide at
the narrowest point), and the density of the traffic
is relatively low’.

It should not be automatically assumed that all
charts compiled from single beam echo sounder
surveys are no longer fit for purpose. Particularly if
used with appropriate discernment and where
relevant, complemented by modern aids to
collision avoidance such as masthead CCTV and
forward looking sonar. An alternative to the latter in
inshore tropical waters and when entering and
leaving harbour, might be a bow lookout with
Polaroid glasses. Such measures, complementing
the existing careful and informed appraisal of
legacy data by Hydrographic Offices, could well
result in some reduction in the perceived magnitude of the re-survey requirement.
Need and Risk Assessment
The figures used to determine percentages of the
seas and oceans remaining poorly charted or not
Figure 6. Ocean routes in the Western Indian Ocean marine Highway Development
project area
Source: Admiralty Ocean Passages for the World NP136 4th Edition. Extract from Admiralty
Chart 4071 © Crown Copyright. Reproduced by permission of the Controller of Her Majesty’s
Stationery Office and the UK Hydrographic Office (www.ukho.gov.uk).
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INTERNATIONAL HYDROGRAPHIC REVIEW
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For example, an enduring Hydrography Risk
Assessment Framework [7], such as that established for a South West Pacific maritime infrastructure comprises the following:

Crowd sourced bathymetric (CSB) data from ships
of opportunity and recreational vessels can be
used to check and supplement SDB; as well as
provide inshore and ocean bathymetry independently. Currently there are issues about data quality,
reliability and chart producers’ liability. The IHB is
being invited to address these by producing
standards and methods of qualifying and identifying CSB data if used for charting inshore waters.
a) A Regional Risk Assessment;
b) An Economic Impact Analysis; and
c) A Regional Risk Assessment Implementation
Plan and funding mechanism agreed by
donors/key stakeholders
This assessment process seems to be a pragmatic
and commercially relevant method to prioritise the
survey needs of the Small Island Developing
States, scattered throughout the region. It is notable that this initiative is led not by a Hydrographic
Office; but by the New Zealand Ministry of Foreign
Affairs and Trade, Aid Programme.

Passage soundings have been and remain a
useful source of information for the nautical
cartographer and ocean mapper. CSB updates this
process and UKHO is a major participant in CSB
trials in Antarctica [10]. Participating cruise ships,
belonging to the International Association of
Antarctic Tour Operators (IAATO), have been fitted
with the ARGUS CSB system which plugs into the
vessel’s navigation system and echo sounder.
Data is recorded and down loaded virtually autonomously with minimal crew involvement.
Filling in the White Space
The President of the Directing Committee of the
IHB acknowledges that alternatives to the deployment of survey ships must be found for “Filling in
the White Space on Charts and Ocean Maps” [8].
This is in the interest not only of safety of navigation but to service the wider blue economy.
Against this background, any viable alternative
methods of obtaining suitable depth information in
a cost effective and reliable manner should be
investigated and promoted.

Crowd Sourcing
Successful surveys have also been carried out in
uncharted Antarctic waters by an IAATO yacht
Xplore [11], provided with survey systems and with
a SHOM hydrographer embarked. The results
were of charting quality. IAATO has clearly identified the potential for suitably equipped yachts and
cruise ship tenders to complement the survey
efforts of government vessels, particularly in
inshore waters. Trials with a hydrographic data
logger are taking place this year under an IHB/
Professional Yachting Association (PYA) initiative.
The ideal would be to see the system installed in
every professionally crewed ship.
Satellite Derived Bathymetry
In the opinion of the IHB [9], shallow water bathymetry derived from multi-spectral imagery, should be
considered as a potential technology for obtaining
bathymetry for charting purposes in areas where
existing surveys are poor or non-existent. Bathymetric and other useful environmental data can be
derived extremely cost effectively by this means.
However, the information content of these data
must be well understood and not regarded as a
replacement for acoustic, Light Detection and
Ranging (LiDAR) or other high resolution surveying
sensors.
Over the past decade, there have been significant
advances in the methods used to derive bathymetry from multi-spectral satellite imagery. It is now
acknowledged that Satellite Derived Bathymetry
(SDB) has the potential to make substantial
improvements to otherwise inadequate charts. It
can provide useful hydrographic data in areas
where existing charting is based on little or no
hydrographic surveying and there is little prospect
of conventional surveys being conducted in the
reasonable future.
Figure 7. Luxury yacht providing Antarctic cruises
Source IAATO presentation to Hydrographic Commission
on Antarctica Meeting December 2013
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The conclusion [12] from the comprehensive IHO
technical assessment visits to the Caribbean
region in 2006 bears setting out in full in the
context of this discussion. It exemplifies the
challenge confronting all developing coastal States
bordering busy seaways and included in the
itineraries of cruise ship operators.
Invisible Data
Large bathymetric data sets from both commercial
and scientific sources remain inaccessible to charting authorities for various reasons. A system
needs to be devised which at least acknowledges
that such data exists and might in time become
generally available; if necessary at a price. This
would certainly not equate to the cost of a repeat
survey.
“This mission covered a sea area of immense
international and regional significance. It
encompassed many of the main passages
from the Atlantic into the Caribbean and
onwards to the Gulf of Mexico and Panama
Canal. The countries bordering these strategic
seaways are small island states or dependencies dealing with a multitude of challenges to
good governance with limited financial and
human resources. Their coastal waters are
traversed by some of the biggest passengercarrying vessels in the world, yet a significant
percentage of those waters have not been
surveyed since the nineteenth century. It is
imperative that the countries visited are assisted to implement appropriate and sustainable arrangements to meet their obligations
under SOLAS Chapter V.”
Coastal States should always endeavour to get
data from Hydrographic Surveys and Marine
Scientific Research conducted within their EEZ.
This is not always straight forward, as interpretation of the UNCLOS provisions concerning the
collection of marine scientific data and Hydrographic Surveying is a contentious area. Additionally, as C-55 states; “… failure to apply IHO S-44
criteria in Marine Scientific Research and offshore
industrial surveys leads to the loss of opportunity
data for SOLAS charting purposes”.
Meeting the SOLAS V/9 Challenge

IHO Initiatives
Subsequent initiatives by the member States of the
Regional Hydrographic Commission (RHC), in
cooperation with UKHO and NOAA have made
some advances in improving charting and other
Marine Safety Information (MSI) services, in
particular around Antigua, British Virgin Islands
and in Belize/Honduras. This suggests that the
revised strategy of staged and focused technical
assistance and engagement of top decision
makers is starting to pay off. Despite this improvement, efforts to establish effective MSI capabilities
remain heavily dependent on outside technical
assistance and responsible national agencies
continue to be under-resourced.
The IHB’s response to its mandate under SOLAS
V/9 was to establish a Capacity Building Committee (CBC), which first met in 2003. This is now the
Capacity Building Sub-Committee (CBSC) of the
Inter-Regional Coordination Committee (IRCC).
The CBC replaced the previous Technical Assistance Coordination Committee whose remit was
narrowly focused on specific education, training
and limited equipment provision. The CBC drew up
the more broadly based Capacity Building Strategy
of the IHO (published in 2006). This better reflected the IHO’s contribution to safety of navigation as complementing that of IMO and the International Association of Lighthouse Authorities (IALA).
At the last International Hydrographic Conference
(IHC) in 2012 the CSBC was tasked to review the
strategy and report to Member States at the
Extraordinary IHC in October 2014. This injunction
perhaps reflects the fact that earlier capacity
building initiatives have been unavailing and
unsustainable. It is now recognised that these did
not engage top decision makers; but rather
assumed that Hydrography per se was selfevidently beneficial to the national well being. That
said, reports from the IHO Technical Visits to the
Caribbean region in 2006 and subsequent ones to
E Africa, Madagascar, Seychelles and Mauritius in
2011/12 clearly reflect a new approach.
There is a similar pattern in the waters of East
Africa and the West Indian Ocean where US, India
and France are undertaking surveys and providing
technical assistance. A series of IHO Technical
visits in 2011 and 2012 established that local MSI
capability is limited and that Capacity Building (CB)
needs a regional component. There was a consensus among visit teams that pooling of survey
equipment for deployment in craft of opportunity
could be beneficial.
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INTERNATIONAL HYDROGRAPHIC REVIEW
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
by
International
The need for collective action between all organisations with responsibility for safety of life at sea
and the protection of the marine environment has
now been recognised. The latter, more than the
potential for loss of life or property, seems to attract the attention of Coastal States’ governments
and funding agencies. Hence the Global Environmental Facility was persuaded to finance both the
Malacca and Singapore Straits and WIO Marine
Highways demonstrations to minimise the risk of
collision involving the VLCC and other vessels
constrained by size, transiting those waters.
Figure 8. Antigua and Barbuda Coastguard craft
with MBES and a positioning and motion sensing
system temporarily fitted
At the last International Hydrographic Conference
in 2012, it was agreed that IHO member States
should commit to working with IMO Member States
to promote the need for improved hydrographic
survey and nautical charting services as required
by SOLAS V/ 9 and to provide support through the
respective IHO and IMO capacity building
programmes. The IHB has since held a Capacity
Building coordination meeting with IMO, IOC,
WMO, IALA and others and has called particular
attention of Regional Hydrographic Commissions
(RHC) to the initiation of the IALA World Wide
Academy [13]. The objectives of the Academy under the headings of Awareness, Assessment,
Analysis and Actions serve as a template for
capacity building to which the IHO subscribes in its
own capacity building strategy.
Source UKHO presentation to Meso American and Caribbean Hydrographic Commission 2011

Concerted Action
Organisations
Non-compliance with SOLAS V/9
Coastal States, in the regions identified in C-55 as
poorly charted, are generally signatories to the
SOLAS Convention, but do not appear to have
accepted their obligations for provision of Hydrographic Services. Many have invested in offshore
surveys and costly technical and legal advice to
establish entitlement to an extended continental
shelf (ECS) beyond 200M. This is understandable
and was driven by the time limit imposed on submissions as well as the prospect of gaining access
to additional seabed resources. The SOLAS
requirement to ensure the safety of navigation
within existing maritime zones has clearly not
engaged decision makers to the same extent. In
most cases the momentum generated by the ECS
submission process and the raising of awareness of maritime matters was not sustained.
Consequently it did not translate into the necessary government actions required to fulfil national
SOLAS obligations despite attempts by donor
agencies to demonstrate the connection.
At the 2013 meeting of the CSBC the UK, drawing
on findings from recent meetings of those RHC for
which it is CB co-ordinator and noting the dramatic
increase in demand for CB made the following
points:
a) That initial assessments of CB requirements
be jointly compiled as one ‘Country Profile’
by IMO, IALA and IHO;
b) That both IHO and IALA should become part
of the team for the IMO Member State Audit
Scheme;
The unfortunate reality has been that donor funded
projects have rarely been sustainable. Boats and
equipment have gradually fallen victim to the
climate and lack of maintenance. Trained personnel have moved on, unable to fully exercise their
new-found skills. Accessory funding has not been
forthcoming and most projects focused on technical provision rather than institution strengthening
and encouraging top level government support.
Recipients have failed to take ownership of
projects or to shoulder any financial burden.
c) The need for a top down approach;
d) Acknowledgement that IHO member States
should derive CB benefits as well as
contributing to the needs of non-members.

Risk Assessment – Economic Benefit
New Zealand has developed a risk assessment
and cost benefit methodology to enable informed
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decision making about investment in improving
charting and MSI for Island States in the SW
Pacific. This seems to be a very sensible approach
and much more likely to result in Government,
Donor and Stakeholder engagement. An initial
assessment of through traffic, local trading patterns and the increasing number of cruise ship
visits in Vanuatu (New Hebrides), has concluded
that updating of the charts and improvements to
and/or refurbishment of aids to navigation would
yield significant economic benefit. As a result a
survey programme has been initiated and work is
currently in progress.


In order to meet the IHO commitment to full ENC
coverage it is considered that CB has been
skewed towards training in ENC production. This is
phase 3 of the IHO CB strategy. It should have
been preceded by enabling the collection and
circulation of nautical information, necessary to
maintain existing charts and publications up to
date. This then would be followed by the creation
of a surveying capability. The feasibility of
implementing phase 3 is acknowledged to be
questionable. Bi-lateral agreements for charting
can provide easier solutions in production and
distribution of ENC through Regional Electronic
Chart Coordination Centres.
Too much technology
In the digital age there seems to be a perception
that developing countries can bypass the essential
learning curve of traditional survey and cartography and move directly to multibeam E/S surveys
and ENC production. This was an unrealised
expectation of the Hydrographic and Maritime
Safety Information (MSI) components of the WIO
Marine Highway Development Project. There is
concern even in established Hydrographic Offices,
that the automation of many critical cartographic
functions could adversely affect product quality.
Industry co-operation
As an example Carnival Australia (the largest
cruise ship operator in the Pacific) is to develop a
public-private partnership that aims to foster
linkages between the cruise ship industry and local
economic development opportunities. Carnival has
identified the need for improved maritime safety
information (MSI) and that the major barrier to
expansion of cruise ship activity in Vanuatu, Tonga
and Fiji is the lack of accurate and adequate
charting.
The above approaches may well be something that
should be looked at in the Caribbean. It is encouraging to note that in 2011 a Marine Superintendent
from a Cruise Ship operator participated in a meeting of the RHC. The company’s ships are over
1,000 feet (305m) in length with a draught of 27
feet (8.2m) and carry a total of 4,000 passengers
and crew. Surveys such as those of St John’s Antigua cited earlier (see Figure 1) are clearly a
response to the needs of such vessels.
Conclusions
The unsatisfactory state of global hydrographic
data and resulting poor quality of global charting
undermines the improvements to the safety of
navigation anticipated from ECDIS. It will require
concerted action from all coastal and Island States
Parties to the SOLAS convention to remedy this.
For many signatories to the convention, the need
to honour their undertakings for the provision of
hydrographic services is not a high priority. There
are more urgent demands on slender human and
financial resources. Any attempt to create a global
network of indigenous cartographic and hydrographic entities for the production of even usage
band 5 and 6 ENC, is unlikely attract the required
support from governments. The current review of
the IHO Capacity Building strategy is therefore
welcomed.
The IHO has for some time encouraged cooperation with industry and representatives of commercial survey companies and equipment manufacturers have enjoyed observer status at meetings of
IHO committees, Working Groups and RHC. They
have also participated in workshops and training
courses. Suggestions have been put to the IHO
Inter-Regional Coordinating Committee for an
industry contribution to the successful implementation of an enduring Capacity Building policy. These
include exploiting the industry’s association with
donor organisations, full participation in education
and training provision, addressing the issue of
sustainability and ultimately collaborating with
developing States in the identification of survey
needs, procurement of survey services and the
design and execution of surveys.
The decline in national hydrographic survey assets
is permanent. A mechanism needs to be found to
harness the resources of the commercial sector to
fill the gap. The successful outcome from the
Introduction to Hydrographic Surveying and Nautical Charting training course in Antigua (see Figure
1) showed what could be achieved in this respect.
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Seafloor Features. Oceanography, Vol. 23, Number 1.
The wider use of SDB could prove cost effect and
attractive to cash strapped administrations, particularly in many small-island developing States. CSB
also has merit as in Antarctica and to verify SDB
elsewhere. Gravity anomalies inferred from
satellite altimetry can assist in the eradication or
confirmation of vigias as potential dangers on
ocean routes.
[4] Accident Investigation findings http://
navysite.de/ssn/ssn711.htm viewed 11 February
2014.
[5] IMO NAV 59/INF.3 31 May 2013 submission by
Australian and Papua New Guinea Growing shipping traffic through the environmentally sensitive
waters of Papua New Guinea.
It is never going to be possible to fill in all the
“white spaces” on the charts and consequently a
rigorous and informed analysis of need and allocation of survey resources is necessary. The
prototype Hydrographic Risk Assessment methodology developed by New Zealand to assist
decision makers to prioritise hydrographic surveys
is one solution to this problem. The WIO Marine
Highway Development Project was an ambitious
attempt to focus survey effort; but was only
partially successful. The hydrographic component
failed to identify the actual rather than the
perceived route survey requirements. Increasingly,
as in Australia and Oceania, the shipping industry
is likely to have to accept more routing restrictions.
This will place the onus on the littoral states to
install and maintain the necessary aids to navigation and MSI infrastructure.
[6] World Bank. 2013. Africa - GEF- Western
Indian Ocean Marine Highway Development and
Coastal and Marine Contamination Prevention
Project. Washington DC; http://
documents.worldbank.org/curated/
en/2013/06/17899495/africa-gef-western-indianocean-marine-highway-development-coastalmarine-contamination-prevention-project viewed
December 2013.
[7] Activity Design Document (ADD): South-West
Pacific Regional Hydrography Programme
http://www.iho.int/mtg_docs/com_wg/CBC/
CBSC10/CBSC10-15A-LINZ%20Activity%
20Design%20Document%20-%20CBSC%20Jun%
2012.pdf viewed December 2013.
The implementation of SOLAS Chapter V concerns
all aspects of navigational safety; of which the
maintenance of nautical charts and publications
and the dissemination of safety critical navigational
information is but one. It is therefore essential that
all international bodies with responsibilities for
oversight of safe navigation coordinate their
regulatory, promotional and mentoring activities.
This is particularly important when raising
awareness of maritime safety issues with governments and funding agencies. Past attempts at
capacity building have been largely unavailing
because recipient countries have not taken ownership of these initiatives.
[8] Ward R. Filling in the White Space on Charts
and Ocean Maps, Hydro International September
2013, vol.19, No. 6.
[9] IHB Paper to 5th meeting of IHO-Inter Regional
Coordination Committee document IRCC5-11A
http://www.iho.int/mtg_docs/com_wg/IRCC/IRCC5/
IRCC5_Docs.htm viewed 20 January 2014.
[10] UKHO paper IRCC5-11B http://iho.int/
mtg_docs/com_wg/IRCC/IRCC5/IRCC5-11BCrowd_Source_Bathymetry.pdf viewed January
2014.
[11] http://www.iho.int/mtg_docs/rhc/HCA/HCA13/
Presentations/HCA1306.3A_IAATO_Report_presentation.pdf viewed 22
Jan 14
References
[1] Survey undertaken by instructors and students
on an IHO capacity building training course
http://www.iho.int/mtg_docs/rhc/MACHC/
MACHC12/MACHC12CB_Antigua_Hydrographic_Course_Report_Final.
pdf viewed February 2014
[2] http://www.artificialowl.net/2009/07/whathappened-to-world-discoverer.html viewed March
2014
[12] Technical Visits to Caribbean states
http://www.iho.int/mtg_docs/CB/CBA/Technical%
20visits/TV07/
Second_phase_Caribbean_States.pdf viewed 23
December 2013.
[3] Sandwell D.T. and Wessel P. (2010) Seamount
Discovery Tool Aids Navigation to Uncharted
[13] IALA WWA Programme Manager presentation
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e-Navigation Underway Conference 2013
http://www.e-navigation.net/index.php?page=the-role
-of-the-iala-world viewed February 2014.
Biography of the Author
Ian RUSSELL is a Fellow of the Royal Institution of
Chartered Surveyors and Member of the Nautical
Institute. Ian has 25 years experience of hydrographic surveys for nautical charting. He is a former
Senior lecturer in Hydrography at Southampton
Solent University with previous consultancy assignments including hydrographic aspects of marine
casualties and implementation of UNCLOS article
76.
[email protected]
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NEXT GENERATION PAPER CHART
By Ian HALLS (Australia)
Abstract
Throughout the ages, the navigation chart has adapted to meet the requirements of the
mariner to ensure safety of navigation. The portrayal of chart information and its physical
presentation on manuscript materials have also changed through innovation and human
factors. In more recent times, the work of the International Hydrographic Organization
(IHO) has established various standards to provide consistency to charting products to
meet a truly global requirement. The transition from a manuscript to a digital electronic
navigation world continues at a rapid pace. A new generation of users are more familiar
and comfortable with electronic technology. One of the challenges facing the IHO is the
future of the paper nautical chart. The ongoing need for paper charts is not the issue discussed in this paper. What is discussed, however, is the portrayal of chart data and the
way in which paper charts may be generated in the future. The issue requires careful consideration to reduce Hydrographic Office (HO) production burdens, maintain relevance and
meet the customers' expectations.
"In matters of style, swim with the current; in matters of principle,
stand like a rock.” Thomas Jefferson.
Résumé
Au cours des siècles, la carte de navigation a évolué pour répondre aux besoins du navigateur afin d’assurer la sécurité de la navigation. La visualisation des renseignements
cartographiques et leur présentation physique sur les supports papier ont également
changé du fait des innovations et des facteurs humains. Plus récemment, les travaux de
l’Organisation hydrographique internationale (OHI) ont établi différentes normes pour rendre cohérents les produits cartographiques en vue de répondre à un besoin véritablement
global. La transition de la navigation avec des documents papier au monde de la navigation électronique numérique se poursuit à un rythme soutenu. La nouvelle génération d’utilisateurs est plus familiarisée et plus à l’aise avec la technologie électronique. Un des
défis auxquels l’OHI doit faire face est l’avenir de la carte marine papier. Le besoin continu de cartes papier n’est pas le sujet de cet article. Ce qui y est abordé, cependant, est la
visualisation des données cartographiques et la façon dont les cartes papier pourront être
produites à l’avenir. Cette question requiert un examen minutieux afin de diminuer les
coûts de production des Services hydrographiques (SH), de préserver la pertinence et de
répondre aux attentes des clients.
« Sur les questions de style, nage avec le courant, sur les questions
de principe, soit solide comme un roc ». Thomas Jefferson.
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Resumen
A través de los tiempos, la carta de navegación se ha adaptado para satisfacer los requisitos del navegante con el fin de garantizar la seguridad de la navegación. La representación de información cartográfica y su presentación física en materiales manuscritos han
cambiado también mediante la innovación y los factores humanos. En tiempos más
recientes, el trabajo de la Organización Hidrográfica Internacional (OHI) ha consistido en
establecer varias normas con el fin de proporcionar coherencia a los productos cartográficos para que satisfagan realmente un requisito global. La transición de un manuscrito a
un mundo digital de navegación electrónica sigue avanzando a un ritmo rápido. Una
nueva generación de usuarios se siente más familiarizada y cómoda con la tecnología
electrónica. Uno de los desafíos a los que se enfrenta la OHI es el futuro de la carta náutica de papel. La necesidad continua de cartas de papel no es el tema que se trata en
este artículo. Sin embargo, de lo que se trata, es de la representación de los datos de las
cartas y del modo en el que podrán generarse las cartas de papel en el futuro. Este tema
merece una cuidadosa consideración para reducir los gastos de producción del Servicio
Hidrográfico (SH), mantener su pertinencia y satisfacer las expectativas de los usuarios.
"En cuestiones de estilo, nada con la corriente; en cuestiones
de principio, mantente firme como una roca.” Thomas Jefferson.
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Linear Scales) and INT3 (Use of Symbols and
Abbreviations).
Whilst the IHO has adopted Karte 1 (INT1) produced by the German Federal Maritime and Hydrographic Agency (BSH, 2011), a single, global
specification for paper chart symbology has been
elusive with many individual HOs developing their
own version of INT1 (e.g. UKHO Chart 5011,
NOAA U.S. Chart No. 1, Canada Chart No. 1,
etc.). Fortunately, these documents basically follow
the IHO INT1 content and structure, and include
additional symbols and abbreviations that have
been locally adopted within a national context. The
key issue is that a mariner looking at charts produced by different HOs can interpret the charted
features correctly through generally adopted portrayal standards.
1. A TALE OF PORTRAYALS
From the very earliest recordings of sailing directions (periploi), to the 15th and 16th century portolans of the Venetians and Genoese, through to the
current paper nautical charts, the depiction of chart
detail has been an art form to serve a multitude of
navigation purposes. The description and portrayal
of real, fictitious, cosmological and embellished
detail, was subject to the current school of thought,
the imagination of the cartographers, the dominant
cultural influences, the artists and the adventurers.
Improvements in navigation methods and technology, the ages of discovery and enlightenment and
more understanding of the real world combined
with innovative charting practices and tools, have
influenced the portrayal of information and the
physical construction of navigation charts as supposition gradually retreated in the face of knowledge.
The S-4 specification is maintained by the IHO’s
Chart Standardization and Paper Chart Working
Group (CSPCWG). The CSPCWG has a set of
defined objectives, operating procedures and guiding principles within its Terms of Reference (IHB,
2013(b)). Due to the diligence of the working group
members over many years and the implementation
of modern, advanced chart production software, S4 and INT1 are mature specifications. Changes to
S-4 are relatively minor and are implemented to
support new charting requirements (e.g. Archipelagic Sea Lanes and various sensitive areas).
1.1 Paper Charts
The depiction of the current paper nautical chart is
the result of some decades of cooperative standardisation effort championed by the IHO and described in the Regulations for International (INT)
Charts and Chart Specifications of the IHO (known
as S-4) [(IHB, 2013(a)]. This publication provides
the framework for modern paper chart construction, colours, symbology and supporting textual
information (Figure 1). S-4 is supported by a number of technical specifications such as INT1
(Symbols, Abbreviations and Terms used on
Charts), INT2 (Borders, Graduations, Grids and
1.2. Electronic Charts
With the development of electronic charting in the
late 1980s, the IHO soon realised that S-4 and its
technical components (INT1 and INT2) would not
Figure 1. A typical INT1 paper chart portrayal
Extract of Chart Aus 28 Copyright Commonwealth of Australia (2008). Used with
permission of the Australian Hydrographic Service.
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engagement, the IHO and ECDIS manufacturers
continue to address and improve these interpretations with the aim of minimising encoding and portrayal variation and ambiguity.
satisfy computerised chart display for the Electronic Chart Display and Information System
(ECDIS). For this reason, a new data portrayal
specification needed to be developed. The Specifications for Chart Content and Display Aspects of
ECDIS (S-52), describes the technical requirements for information display, symbology, environmental condition colour palettes, display screen
configurations and various calibrations. S-52 includes Annex A - the Presentation Library (PL)
(IHB, 2010(a)), and is maintained by the IHO’s
Digital Information Portrayal Working Group
(DIPWG). The objective of this group is to maintain
the IHO's specification for colours, symbols and
display rules used to show Electronic Navigation
Chart (ENC) information on ECDIS in a safe and
ergonomic manner (see Figure 2). The membership of these working groups reflects wide international cooperation and this resulted in the general
global acceptance of their resultant work.
2. THE CHALLENGE OF TWO CHART
WORLDS
In the late 1980s when ECDIS was first conceptualised and the early systems were being prototyped, there was much speculation about the future of the paper chart. It was not uncommon to
hear early statements that paper charts would not
exist beyond 2000. It has hard to believe that after
20 years, the paper chart is still a preferred navigation tool by many mariners.
The continued preference for the paper chart in an
ever-increasing electronic age is the result of a
number of factors:
Rather than being a paper-based portrayal specification such as INT1, the PL is provided in a machine-readable format so that electronic chart
manufacturers can use it in their technology. The
use of a standard set of symbology instructions
should minimise the interpretation of symbology
rules. This unfortunately is not always the case
and a number of system manufacturers have either
implemented the library with their own coding interpretations or developed their own libraries creating
inconsistency issues with ENC data portrayal
(Mohasseb, 2013). Through intensive stakeholder

Users are familiar with long-used, paper chart
products. Often user’s charts are marked up
with historical routes or other important information;

HOs have taken a long time to achieve a satisfactory level of ENC coverage. This has
meant that HOs need to produce and maintain multiple products, often using multiple
production systems that compound complex
issues in production and maintenance work-
Figure 2. S-52 portrayal of the same area depicted in Figure 1
Extract of ENC Cell AU5XX24 Copyright Commonwealth of Australia (2008). Used
with permission of the Australian Hydrographic Service.
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flows, training, competency and technology
and data refresh;
3. PAPER CHARTS AND SAFETY OF LIFE
AT SEA (SOLAS) CONVENTION

The legislative process of the International
Maritime Organization (IMO) has taken many
years to mandate compulsory use of ECDIS
resulting in a slower uptake of ECDIS technology and the necessary formal training of
mariners to appreciate the technology and
gain the necessary competencies;

Official ENC data is used predominantly in
type-approved ECDIS on large ships. A significant market segment doesn’t require
ECDIS technology (e.g. recreational users,
fishing, small commercial vessels). For these
users, official ENCs, non-official vector charts,
raster charts and paper charts can all be used
to meet their requirements;
The adoption at the IMO's Maritime Safety Committee 86th session (MSC86) of the amendments
to SOLAS (IMO, 1974) regarding mandatory carriage for ECDIS equipment for ocean-going ships
has an important impact on the future need for paper nautical charts (see Figure 3). Under the SOLAS revisions, the decision must be made either to
fit vessels with dual or single ECDIS. Both must
comply with the ECDIS performance standard and
will require a back-up plan whose demands will
vary between flag States. In the dual-ECDIS case,
bridge staff will be able to significantly reduce (in
some cases down to zero) their use of paper
charts. In the single-ECDIS case, they will likely
keep the paper chart as backup.

Many mariners are so familiar with the paper
chart that a change in presentation, functionality and trust in technology can be difficult to
embrace;

The variety of cheaper electronic charting
systems (ECS) product offerings, the varying
levels of data quality and competitive business interests lead to a confused electronic
chart market-place.
In Australia, the Australian Maritime Safety Authority (AMSA) released Marine Notice 7/2012 outlining Guidance of ECDIS for ships calling at Australian Ports. In accordance with IMO resolutions,
AMSA considers the following will meet the backup requirements for ECDIS (AMSA, 2012):
“An independent, fully compliant second ECDIS unit, connected to ship’s
main and emergency power supply
and connected to systems providing
continuous position fixing capability;
or
Figure 3. ECDIS Compliance Dates for SOLAS (UKHO, 2013)
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Adequate and up to date paper charts
(including relevant large scale charts)
necessary for the intended voyage.”
4.1. Official ENC-Derived Paper Charts
If a paper nautical chart is to exist in the future,
what should it look like? Is it practical or economically feasible for HOs to continue to publish paper
chart products with different portrayals? Will this be
confusing to the market place?
The IHO describes a nautical chart in S-66 (IHB,
2010(b)) as:
“Nautical charts are special purpose
maps specifically designed to meet the
requirements of marine navigation,
showing amongst other things depths,
nature of the seabed, elevations, configuration and characteristics of the
coast, dangers, and aids to navigation.
Nautical charts provide a graphical representation of relevant information to
mariners for executing safe navigation.
Nautical charts are available in analogue form as paper charts, or digitally
as electronic charts.”
Irrespective of the ENC/paper chart equivalency,
many HOs can produce INT1 paper charts fairly
easily from an ENC source. The primary hydrographic software vendors all provide an INT1
paper chart output. Hence, there is no impediment
to this capability continuing. However, as uptake of
ENCs continue, can users be expected to put up
with two different portrayals of the fundamental
navigation data? An alternative approach is for
HOs to publish paper charts with a predominantly
S-52 (ENC) presentation and transition away from
the traditional INT1 portrayal.
A key component of nautical charting world-wide is
standardisation of portrayal. This is emphasised in
IMO SOLAS Chapter V Regulation 9, para. 3 (IMO,
1974):
To assist in the adoption of electronic charts, the
author believes that there is merit in considering
the need to transition INT1 paper chart portrayal to
a S-52 style portrayal. From a practical production
aspect and debatably a customer perspective, it
makes little sense to retain two separate product
portrayals. In a small and limited customer market,
the major HO production software vendors all support S-52 portrayal in their symbol libraries. All of
the software systems are relatively mature and
whilst they can support both INT1 and S-52, a transition to one portrayal specification can utilise the
best of both specifications (e.g S-52 for colours
and symbols, INT1 for graticules, marginalia, title
blocks and text, etc.). As part of the IHO’s S-100
family of product specifications, S-4 could/should
be replaced by a new S-10x Product Specification:
ENC-Derived Paper Chart.
“ensure the greatest possible uniformity
in charts and nautical publications and
to take into account, whenever possible,
relevant international resolutions and
recommendations.”
4. THE FUTURE OF PAPER CHARTS
Given the changes to the implementation of
ECDIS, what is the future of the paper chart? In a
2011 article, the then UKHO CEO, Mike Robinson,
expressed a view that paper charts would still be
used for many years, even if they were only used
in a "get me home" scenario. Despite a prediction
that the sale of UKHO digital charts will exceed the
sale of paper charts around 2018, there will still be
a requirement to provide paper chart products to
meet the varied usages and this will continue to be
a production and maintenance issue for all HOs
(Robinson, 2011).
4.2.
User-generated Non-official paper
charts
In the world of "apps", it should be possible for users to create and print their own ENC-derived
charts. These charts can be plotted from the users
own ECDIS or ECS technology where the ENC
data has already been purchased. In this case the
plot could be generated from the System ENC
(SENC) or from the purchased ENC product. HOs
will need to consider a pricing model for the ENC
to include some level of cost recovery for usersourced plotting. Chart agents and other value
added resellers may also provide a plotting service.
In a world that is rapidly changing in technology (in
matters of style, swim with the current), along with
a technically-savvy younger generation of users, it
is time to look critically at what the paper chart
represents and how it can be provided in different
ways to a changing user-base without compromising navigational safety (in matters of principle,
stand like a rock).
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Available data: Where ENC coverage is not fully
available, the paper plot may contain Raster Nautical Chart (RNC) content. The ENC content should
always take precedence and some rules will be
required to stop users from plotting RNC versions
of the large portions of paper charts.
5.
S-100 PRODUCT SPECIFICATION
FOR A ENC-DERIVED PAPER CHART
The traditional paper chart specifications are well
described through S-4, INT1 and national variants.
However, for the portrayal of ENC data on a paper
format, it is recommended that a new S-10x product specification within S-100 be developed and
managed either by a sub-group of one of the
current IHO portrayal working groups or by a new
technical working group. The purpose of the new
product specification is to establish the minimum
requirements for the portrayal of ENC data on a
manuscript format whilst maintaining an appropriate level of maritime navigation safety. In developing such a specification, a number of issues need
to be considered.
Data Content: similar to S-52, a minimum content
of ENC data (e.g. Base) is required. The user
should then have the ability to add extra content to
the display.
Projection: At a certain scale, the output plot
should be projected to aid the intended usage. For
large scale situational awareness, a UTM projection may be best. For scales smaller than 1:75,000
where the chart may be used for course plotting
and navigation, the plot should be output in a Mercator projection.
Colours: S-52 provides various colour palettes.
For paper chart plots, the “bright-day” palette is
likely to be the preferred colour palette.
5.1 Data portrayal
S-52 specifications were designed for computer
displays and not paper output. Hence, the ENC
portrayal will not be aesthetic to the eye from a
traditional paper chart user perspective. New symbols would need to be added to account for cartographic features such as a compass rose. With
increased uptake of ENCs, users should be more
familiar with ENC portrayal and so over time, portrayal interpretation issues should also reduce. To
assist mariners with ENC portrayal, the UKHO has
already issued the ECDIS version of INT1 NP5012 Admiralty Guide to ENC Symbols used in
ECDIS (UKHO, 2012).
Symbology: S-52 supports a simplified and traditional symbology palette. The user should be able
to select the palette they are most familiar with.
Some additional cartographic symbols will need to
be developed.
Explanatory/Cautionary Notes: These notes are
provided to assist the mariner to interpret potential
navigational issues (e.g. chart omissions, dangers,
etc.) or provide advice on where to find additional
information (e.g. maritime boundaries). In the ENC,
these notes are provided as text and/or picture
files. Rather than plot the note content on the paper copy, the user could be given the option to
print any relevant files separately.
5.2 Paper Plot Layout Elements
Certain “elements” need to be included in the plot
layout to assist the mariner using the derived paper chart:
6. PLOTTING SERVICES
HOs can continue to provide plotting services for
official paper charts. In many cases, chart plotting
is now undertaken using Print on Demand (POD)
technology rather than offset lithographic printing.
POD provides options for plotting charts as either
traditional INT1 portrayal or ENC-derived portrayal
at large formats. Most users do not have access to
large A0 plotters. Hence, large format plotting,
from an economic perspective will remain with the
HO, any contractors or potentially chart agents or
specialist service agencies. Most users will only
have access to A3/A4 printers at most. The challenge for using A0 plotters on vessels is the maintenance of consumables (i.e. inks and paper)
which can be bulky, messy, expensive and susceptible to temperature and humidity.
Graticule: Simplified latitude and longitude grid/
graticule
Scale bar: Simplified scale bar
Marginalia: Plot date, ENC EN/ER update status,
Geographic extents, Producer agency ENC cell
names used as the source, copyright and disclaimer statements.
Scale: The scale of the plot will be determined by
various user-defined options – paper size, area
coverage, etc. Some warning notation may be required if the inappropriate navigation usage or
ENC scale is used for plotting. This may be similar
to the “overscale” warning currently shown on
ECDIS displays.
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IHB, 2010(a). Specifications for Chart Content and
Display Aspects of ECDIS (S-52) (including Annex
A IHO Presentation Library for ECDIS (PL) Ed. 3.4,
January 2008), Ed. 6.0, March 2010.
7. LEGAL ISSUES
If a paper chart is plotted from the official HOpublished ENC or RNC data, or from an approved
SENC, and it has been output using the minimum
required portrayal settings, it should be deemed
suitable as an official and legal product. Some criteria may need to be established to ensure that the
plotted output is legible in terms of scale and
colours (rather than a grayscale printout).
IHB, 2010(b). Facts about Electronic Charts and
Carriage Requirements (S-66), Ed. 1.0.0, January
2010.
IHB, 2013(a). Regulations for International (INT)
Charts and Chart Specifications of the IHO (S-4),
Ed. 4.4.0, September 2013.
8. CONCLUSIONS
IHB, 2013(b). Chart Standardization and Paper
Chart WG (CSPCWG) Terms of Reference,
www.iho.int/mtg_docs/com_wg/TOR/
CSPCWG_TOR.pdf, viewed 1/6/2013.
The increasing adoption of ENCs and the changes
in mandatory carriage requirements for SOLAS
vessels will result in mariners using a product that
has significant portrayal and capability departures
from the traditional INT1 paper chart and derived
raster navigation products currently in the market
place. Should users have to put up with multiple
navigation chart portrayals or should there be only
one product portrayal based predominantly on the
ENC with additional portrayal functionality to provide "cartographic representations"?
IMO, 1974. International Convention for the Safety
of Life at Sea (SOLAS) as amended, London.
http://www.imo.org/ourwork/facilitation/documents/
solas%20v%20on%20safety%20of%
20navigation.pdf viewed 20 Dec 2013.
Mohasseb, M. Anomalous ECDIS Operations, International Hydrographic Review, No. 9, May 2013,
pp47-52.
The author does not question the ongoing need for
paper charts - only how paper chart content should
be portrayed to users. At all times the principle of
safety of navigation cannot be compromised, but
this doesn't preclude looking at opportunities to
streamline the production or to simplify the provision of derived paper products from an official ENC
source. There is no doubt that such considerations
will spark debate. However, from experience of
witnessing the battle that some HOs had with the
ECS entrepreneurs of the early 1990s, the IHO
needs to decide if this really is an issue and be on
the front foot in defining an appropriate specification. Otherwise, industry will dictate the capability.
Robinson, M. UKHO strives for worldwide leadership in hydrographic information, Hydro INTERNATIONAL, Vol. 15, No. 1, January/February 2011.
UKHO, 2012. Admiralty Guide to ENC Symbols
used in ECDIS, NP5012, 1st Edition, 2012.
UKHO, 2013. http://www.ukho.gov.uk/Media/News/
Pages/What_Mandation_Means.aspx viewed 18
Dec 2013.
10.
The opinions expressed in this paper are those of
the author and do not necessarily reflect those of
the Hydrographer of Australia or the Royal Australian Navy.
BIOGRAPHY OF THE AUTHOR
Ian HALLS commenced work at the Australian
Hydrographic Office (AHO) in 1979 as a trainee
nautical cartographer and has been involved in the
development of nautical data management and
chart production systems since the mid-1980s.
This period included serving several years on IHO
ECDIS/S-57 technical committees. He is a past
Director of HSA Systems Pty Ltd and resumed
working at the AHO in 2009 after 15 years in private industry undertaking systems engineering,
hydrographic surveying and charting activities.
9. REFERENCES
AMSA, 2012. Guidance on ECDIS for ships calling
at Australian ports, Marine Notice 7/2012, Australian Maritime Safety Authority.
BSH, 2011. Karte 1 (INT1) Symbols, Abbreviations
and Terms Used on Charts, 7th Edition, German
Federal Maritime and Hydrographic Agency
(Bundesamt für Seeschifffahrt und Hydrographie),
2011.
He is currently managing the military hydrographic
data, products and services section of the AHO.
Ian is also working with a small dedicated team to
sustain the Digital Hydrographic Database solution
developed in early 2000. This involves the
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software, hardware and ICT refresh of the various
source data receipt, validated data, production,
distribution, and workflow sub-systems using an
enterprise architecture approach.
[email protected]
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RESEARCH ON THE DESIGN OF SURVEY LINES
IN A MARINE MAGNETIC SURVEY
By BIAN Gang, XIA Wei , JIN Shaohua, XIAO Fumin, SUN Xinxuan, CUI Yang
Department of Hydrography and Cartography, Dalian Naval Academy (China)
Abstract
The planning of a marine magnetic survey requires careful consideration in the design of
the survey lines to ensure the results of the survey meet expected standards. This paper
describes various evaluation methods to determine an optimal survey line layout for a
marine magnetic survey that conforms to Chinese marine magnetic survey Standards.
Various survey line layouts are tested using simulated data to evaluate the interpolation
precision between neighbouring survey lines and the magnetic anomaly map. The test
results provide a recommended process to determine the rationality and the optimal layout
of the survey line pattern for undertaking marine magnetic surveys.
Résumé
La planification d’un levé magnétique marin requiert un examen minutieux de la conception
des profils de sonde pour assurer que les résultats du levé répondent aux normes
attendues. Cet article décrit différentes méthodes d’évaluation en vue de déterminer une
présentation de profil de sonde optimale pour un levé magnétique marin qui soit conforme
aux normes des levés magnétiques marins chinois. Diverses présentations de profils de
sonde sont testées à l’aide de données simulées dans le but d’évaluer la précision de
l’interpolation entre profils de sonde voisins et la carte des anomalies magnétiques Les
résultats des tests permettent de recommander un processus pour déterminer la rationalité
et la présentation optimale du schéma de profil de sonde afin d’entreprendre des levés
magnétiques marins.
Resumen
La planificación de un levantamiento magnético marino requiere una cuidadosa consideración en el diseño de las trayectorias a seguir para garantizar que los resultados del
levantamiento cumplan las normas esperadas. Este artículo describe los diversos métodos
de evaluación para determinar una disposición óptima de las trayectorias para un levantamiento magnético marino que sea conforme a las normas chinas de levantamientos
magnéticos marinos. Se han efectuado pruebas sobre varias disposiciones de trayectorias,
utilizando datos simulados para evaluar la precisión de la interpolación entre trayectorias
vecinas y el mapa de anomalías magnéticas. Los resultados de las pruebas proporcionan
un proceso recomendado para determinar la racionalidad y la disposición óptima del patrón
de trayectorias para llevar cabo levantamientos magnéticos marinos.
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according to Table 1, the precision of the magnetic
anomaly map can not be evaluated.
INTRODUCTION
The planning of a marine magnetic survey line
uses a series of crossing main survey lines and
reference survey lines to provide an optimal survey
network. However blank areas can exist between
survey lines. Thus the design of the survey line
pattern is a primary requirement for marine magnetic surveys and is important in the assurance of
survey precision and efficiency.
Applying the survey line requirements from
Table 1, two kinds of unsatisfactory results will be
produced: (1) Survey lines spacing will be too
dense. Although the requirement of the survey precision can be satisfied, the work load and the total
survey expense will be significantly increased and
the survey efficiency will be correspondingly decreased; and (2) the survey lines spacing will be
too sparse, so the requirement of the magnetic
anomaly map precision will not be met, the extended measurement work will have to be developed and the survey efficiency will also decrease.
There are similarities and differences between marine magnetic surveys and other marine surveys.
In a bathymetric survey, the fair chart mostly comprises depth points and derived depth contours
assist as a secondary portrayal. In a marine magnetic or a marine gravity survey, the final survey
product is mainly represented by contours, which
is called a marine magnetic anomaly map or marine gravity anomaly map.
After analysis and investigation, the authors consider that the precision of survey points and the
magnetic anomaly map must also be prescribed.
This can meet the needs of different practical applications such as military, navigation, science research, geological exploration, marine exploitation,
underwater detection, marine engineering etc.
Given the unambiguous precision of the marine
magnetic anomaly map, the appropriate survey
line spacing can be determined by the surveying
engineer, and the practical magnetic characteristics fully considered.
Similarly, compared to a marine gravity survey, the
spatial variations of magnetic anomaly values are
rapid and complex. Therefore, the design of the
survey lines in a marine magnetic survey is even
more important than in a marine gravity survey.
The design of the survey lines is discussed in this
paper and the requirements in the design of survey
lines are described in the Specifications for Marine
Magnetic Surveys in China (refer to Table 1).
Two basic problems exist in the survey line layout:
(1) What is an optimal survey line layout? (2) How
can we design optimized survey lines? Therefore
three detailed problems must be analyzed and discussed: (1) the influence of survey line direction;
(2) the influence of survey line spacing, and (3) the
factors that can be applied to describe these influences. In this paper, the problems above have
been resolved and methods have been tested using simulated data.
Table 1: The line spacing in different survey order
given
by Specifications for Marine Magnetic
Survey
2. THE EVALUATION METHODS OF THE
SURVEY LINE LAYOUT
A magnetic anomaly contour map is the main
product from a marine magnetic survey. The
spatial distributions of the magnetic anomaly in a
survey area can be distinguished and the magnetic
anomaly information provided for different applications. To obtain spatial distributions of the
magnetic anomaly between survey lines, observed
values on a survey line can be used to interpolate
the values between two neighbouring lines. The
interpolating precision can be applied to reflect the
representative capability of the magnetic anomaly
in a survey area. Accordingly, the magnetic
anomaly map and the interpolating precision can
been used to evaluate the rationality of the survey
line layout.
In Table 1, the survey precision requirements are
listed in each Order (the precision is calculated by
the crossing point of main lines and reference
lines). However, the required precision of the magnetic anomaly map (being the survey product) is
not prescribed. The line spacing in each survey
Order is decided by the corresponding survey
scale (corresponding distance of 1cm on survey
map), rather than by the characteristics of the
magnetic anomaly. Therefore some problems exist
when undertaking a practical survey. On the one
hand, for certain magnetic anomaly map precisions, the corresponding survey Order is unknown.
On the other hand, if the survey Order is given
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2.2 Evaluation with interpolation precision
between two neighbouring lines
2.1 Evaluation with magnetic anomaly map
A marine magnetic anomaly map is the most intuitive and expressive output from a marine magnetic
survey. Reviewing the magnetic anomaly map, the
general trend and distribution of the magnetic
anomaly can be distinguished, and any significant
magnetic anomaly can be determined by the magnetic anomaly contours.
2.2.1 The concept of the interpolation between two
neighbouring lines and its precision
The marine magnetic survey line pattern consists
of main survey lines and reference lines (a reference line is also called a cut line or tie line in an
aeromagnetic survey). To plot a magnetic anomaly
map, the magnetic anomaly information of the
blank area between survey lines must be interpolated. Therefore the plotting precisions of the
magnetic anomaly map are estimated by the precision of observed data and interpolated data.
Evaluating the magnetic anomaly map means that
we can compare a simulated magnetic anomaly
map with a true magnetic anomaly map obtained
by a given survey line layout. The rationality of the
survey line layout can be evaluated by the display
of the output map to determine if the survey
requirements are met.
After analysis and discussion,
standards can be detailed as follows:
However, the interpolating precision is mainly
determined by variable characteristics of the magnetic anomaly and survey line spacing. So the
main aim of the survey line layout is to determine
the survey line spacing. By controlling and adjusting the interpolating precision, the given precision
of the survey product can be determined. The
requirement of the survey line layout is related to
the requirement of interpolating precision. To meet
different interpolating precisions, the survey line
layout can be different. Hence, the interpolating
precision is an important value to determine the
rationality of the survey line layout.
evaluating
(1) Magnetic anomaly maps are considered to be
consistent, whereby the general trend of the
magnetic anomaly can be determined and the
detailed magnetic anomaly in the given magnitude
can be identified.
(2) Magnetic anomaly maps are considered to be
basically consistent, whereby the general trend of
the magnetic anomaly can be approximately determined and the detailed magnetic anomaly in the
given magnitude can usually be identified.
Actually, the designed reference lines can be
adopted to evaluate the interpolating precision.
The middle point of two neighboring survey lines
can be used to estimate the interpolating precision.
(3) Magnetic anomaly maps are considered to be
basically consistent, whereby the general trend of
magnetic anomaly can be approximately determined, but the detailed magnetic anomaly in the
given magnitude is difficult to identify.
(4) Magnetic anomaly maps are considered to be
inconsistent, whereby the general trend of the
magnetic anomaly can not be determined and the
detailed magnetic anomaly in the given magnitude
cannot be identified.
In the Standards above, when the magnetic anomaly map contrast accords with (1) or (2), considering the survey error, the survey line layout is considered rational. When the magnetic anomaly map
contrast accords with (3) or (4), the survey line
layout is considered irrational.
Figure 1: The sketch map of evaluating with the middle
point
In Figure 1, the number of main lines (Ln) and reference lines (Cn) is m and n in a survey area. The
main lines are perpendicular to reference lines,
and main line spacing is d, and there are m´n
cross points.
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This expression reflects the relation of the MSE of
the magnetic anomaly difference, the MSE of the
observation and the linear interpolation model
error.
On each reference line, middle point P is selected
as a reference point to evaluate the interpolating
precision. For each reference point, the difference
between the interpolated value and the true value t
can be obtained.
mt and mT can be calculated through observed
data of the whole survey area. That is,
(1)
In expression (1), TI represents the magnetic
anomaly value which is interpolated by the corresponding observed value on two neighboring survey lines. TR is true value of middle point observed
on the reference line. As the interpolated magnetic
anomaly value TI and true value TR on the reference line is irrelevant, we can derive the following
formula.
(7)
In expression (7), the number of the reference
points P is N. The number of main lines and reference lines is m and n, which are crossed, so reference points can be expressed as N=(m-1)×n.
(2)
(8)
In expression (2), mt represents the mean square
error (MSE) of the magnetic anomaly difference, mI
is MSE of the interpolated value, mR is the interpolation precision of the observation value.
The MSE of interpolated value mI can be analyzed
in the following text. Linear interpolating is a common method in survey processing, so the next
formula is expressed as follows.
In expression (8), ∆ is the difference of the
observed value of the reference point, which are
respectively obtained by the main and reference
lines.
Through expression (6), the precision of the linear
interpolation model error of the whole survey area
can be obtained.
(3)
(9)
In expression (3), T1 and T2 represent the
observed values on two neighboring main lines
which cross a reference line. ε is the corresponding model error, which can be obtained by linear
interpolation. With a different interpolating method,
the model error can be different. Because the
observed values on each main line are independent, the law of propagation of errors is followed.
The linear variation characteristics of the magnetic
anomaly can be reflected directly. The smaller the
number of mε, and hence, the smaller the survey
line spacing, the better the linear characteristics of
the magnetic anomaly.
From the expressions above, a precise control
situation can be analyzed. For example, when the
requirement of the magnetic anomaly interpolation
precision is less than the observation precision, mI
≤ mR, and expression (5) becomes.
(4)
(5)
(10)
The expression above denotes the relation of the
precision and interpolated value. With (5) and (2),
then:
The requirement of the linear interpolation model
error of the whole survey area is.
(6)
(11)
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Neglecting the non-linear part in function T(x),
when n>2, expression (14) simplifies to:
Combining expression (6), expression（11）now
becomes:
(12)
The
requirement
of
the
precision
will
(14)
be:
The expression, is the non-linear part of function
T(x) and T˝(ξ) is the gradient of T(x) along the X
axis.
2.2.2 The interpolation model error and its
expression
Combined with expression (13) and (14), the
observed values T(x1) and T(x2) in neighboring
main lines of point x1 and x2 can be expressed as
follows.
In Figure 2, the direction of the reference line is
along the axis X, where x1, x2 are the coordinates
of observed magnetic anomaly values in neighboring survey lines, and xp is the coordinate of the
middle point along the reference line. The coordinate along the main survey lines are the same.
(15)
(16)
When the linear interpolation is adopted, the
magnetic anomaly value T(xp)́ on the interpolating
point can be expressed as:
(17)
When expression (15) and (16) are adopted in
expression (17) and compared to T(xp), the
interpolating model error on point xp is:
Figure 2: The sketch map of linear interpolation
between lines
(18)
Suppose that the magnetic anomaly function is
expressed as T(x), which is deemed as the true
value. In interval (x1, x2), the differential coefficient
is (n+1). On the middle point xp of the reference
line, the function T(x) can be expanded as a Taylor
series.
For x2–x1=d, expression (18) can be finally
concluded as:
(19)
From expression (18), the conclusion is that the
larger the survey line spacing, the smaller the
interpolation precision will be. This also leads to an
increased complication in the variation of the
magnetic anomaly gradient. This is consistent with
the analysis described in the Section 3.
(13)
In expression above, Rn(x) is the interpolation
residual part.
Expression (19) is deduced based on the direction
of the reference line along the X axis. Actually
expression (19) can represent the interpolation
error in any direction of the reference line.
35
INTERNATIONAL HYDROGRAPHIC REVIEW
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Combined with the evaluation methods above, the
rationality of the survey line layout can also be
evaluated. The error sources of the magnetic
anomaly map and the description of its precision
are listed in Table 2.
These types of simulation have been confirmed
and complement each other.
3.1 Analyzing
simulations
Table 2: The error sources of magnetic anomaly
map and the description of its precision
of
background
data
for
The magnetic anomaly maps of uniform distribution (Simulation background A, in Figure 3) and
non-uniform distribution (Simulation background B,
in Figure 4) have been adopted as background
data to simulate and analyze. The data sources
respectively are marine magnetic surveys of a
certain area in 2002 and 2006. Corresponding corrections have been completed and the grid data of
50m×50m have been interpolated, which are taken
as real data in later simulations.
X(m)
10000
8000
6000
3.
INFLUENCE OF SURVEY LINE
LAYOUT ON SURVEY RESULT
4000
2000
In designing the marine magnetic survey, the survey line layout includes the determination of the
survey line direction and spacing. The evaluation
method can be used to evaluate the rationality of
the survey line layout.
0
0
2000 4000 6000 8000 10000 12000 14000 16000 18000 20000 Y(m)
Figure 3: Magnetic anomaly map for simulation
background A (contour interval 10 nT)
X(m)
10000
The known (from prior surveys) magnetic anomaly
maps have been adopted. When different survey
line layouts are applied and simulated magnetic
surveys carried out, the interpolation precisions are
calculated and the magnetic anomaly contour
maps are plotted with simulated data. The change
of interpolation precisions and comparisons of the
magnetic anomaly maps are analyzed to determine the influence of the survey line layout on the
overall survey result.
8000
6000
4000
2000
0
0
2000
4000
6000
Y(m)
8000 10000 12000 14000 16000 18000 20000
(a) Contour interval 5 nT
The background data for simulations have been
introduced and analyzed. The simulation and
analysis are divided into three types:
X(m)
10000
1. The influence of the survey line layout on the
interpolation precision (without the observation
noise).
6000
8000
4000
2000
2. The influence of the survey line layout on the
magnetic anomaly map (without the observation
noise).
0
0
2000
4000
6000
8000 10000 12000 14000 16000 18000 20000
(b) Contour interval 10 nT
3. The influence of the survey line layout on the
interpolation precision and magnetic anomaly map
(with the observation noise).
Figure 4(a) and (b): Magnetic anomaly map for
simulation background B
36
Y(m)
INTERNATIONAL HYDROGRAPHIC REVIEW
MAY 2014
The contour interval in Figure 4(a) is 5nT and is
too dense to compare, so the contour interval of
10nT has been selected (Figure 4(b)) for comparison and analysis. From Figure 4, the distribution of
the magnetic anomaly is uniform, the maximum is
50.90nT, the minimum is -128.06nT, and the
average is -40.23nT. The direction of the magnetic
anomaly gradient is 153.89°.
The aim of the simulations above are: (1) The impact of the survey line spacing on interpolation
precision with the same survey line direction.(2)
The impact of different survey line directions on the
interpolation precision with the same survey line
spacing.
The simulation scheme above has been conducted
without observation noise (mR=0), so combined
with formulae (2) and (5).
3.2 Influence of survey line layout on interpolation precision (without observation noise)
（20）
The influence of the survey line layout on the
survey result can be divided into the impacts of the
survey line direction and the survey line spacing.
Therefore, different survey line directions and
survey line spacing have been simulated and
calculated. For analysis and outcomes, the representative simulation schemes are listed in Table 3.
The sketch map of survey line direction shown as
in Figure 5 ( a is the angle of total gradient direction of the magnetic anomaly and the X axis).
The magnetic anomaly map of simulation
background A (in Figure 3) is the known magnetic
map and the influence of the survey line layout has
been analyzed. The interval of the simulated
survey points is 50m and the reference line
spacing is 1000m. The simulation has been
completed according to Table 3 with the results
listed in Table 4 and charted in Figure 6.
Table 4: The interpolation precision in different survey
line layouts of simulation background A(Unit nT)
Table 3: Simulation scheme of influence of survey line
layout
Figure 5: The sketch map of survey line direction
37
The interpolation precison of magnetic anomaly(nT) ）
INTERNATIONAL HYDROGRAPHIC REVIEW
3.5
3.4
3.3
3.2
3.1
3
2.9
2.8
2.7
2.6
2.5
2.4
2.3
2.2
2.1
2
1.9
1.8
1.7
1.6
1.5
1.4
1.3
1.2
1.1
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
MAY 2014
Table 5: The interpolation precision in different survey
line layouts of simulation background A(Unit nT)
Total gradient
The axis X
The axis Y
Perpendicluar to total gradient
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2 2.1
The line Spacing(km)
Figure 6: The interpolation precision in different survey
line layouts of simulation background A
The interpolation precison of mag netic anom aly(nT) ）
The magnetic anomaly map of simulation
background B (in Figure 4) is the known magnetic
map and the influence of the survey line layout has
also been analyzed. The interval of the simulated
survey points is 50m and the reference line
spacing is 1000m. The simulation has been
completed according to Table 3 with the results
listed in Table 5 and charted in Figure 7.
In Figure 6 (corresponding to Table 4 results) and
Figure 7 (corresponding to Table 5 results), there
are large discrepancies in the interpolation precision in different survey line directions. The
maximum discrepancy is 2.19nT in simulation
background A (uniform distribution) and 4.21nT in
simulation background B (non-uniform distribution).
Therefore, the significance of the selection of the
survey line direction has been adequately
explained.
The conclusions from the simulations are:
The highest interpolation precision is obtained
when the survey line direction is the total gradient
direction. The lowest interpolation precision appears along the perpendicular of the total gradient.
The closer the survey line direction to the total gradient direction, the higher the interpolation precision. Meanwhile, the discrepancy of the interpolation precision in a certain survey line direction will
increase as the survey line spacing increases.
7
6.8
6.6
6.4
6.2
6
5.8
5.6
5.4
5.2
5
4.8
4.6
4.4
4.2
4
3.8
3.6
3.4
3.2
3
2.8
2.6
2.4
2.2
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
Total gradient
The axis X
The axis Y
Perpendicluar to total gradient
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2 2.1 2.2
The line Spacing(km)
Figure 7: The interpolation precision in different
survey line layouts of simulation background B
38
INTERNATIONAL HYDROGRAPHIC REVIEW
MAY 2014
been adopted, the simulation content and the aims
are listed in Table 6. The simulated magnetic
anomaly maps and the comparative results are
shown in Figures 8 to 12. For comparison
purposes, the known and simulated magnetic
anomaly maps have been plotted together in the
same map display - the known magnetic anomaly
contours are plotted as solid lines and the
simulated magnetic anomaly contours are plotted
as dashed lines. The contour interval is 10nT.
3.3 Influence of survey line layout on magnetic
anomaly map (without observation noise)
To analyze the influence of the survey line layout
on the magnetic anomaly map and discuss the
consistency of interpolation precision, contrastive
simulation and analysis have been carried out.
Based on the background B simulation, in which
the non-uniform distribution magnetic anomaly has
Table 6: Simulation scheme of influence on magnetic anomaly map
X(m)
X(m)
10000
10000
8000
8000
6000
6000
4000
4000
2000
2000
0
0
2000
4000
6000
Y(m)
8000 10000 12000 14000 16000 18000 20000
0
0
2000
4000
6000
Y(m)
8000 10000 12000 14000 16000 18000 20000
Simulation N°2 (Line spacing is 0.9km)
Simulation N°1 (Line spacing is 0.3km)
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INTERNATIONAL HYDROGRAPHIC REVIEW
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X(m)
X(m)
10000
10000
8000
8000
6000
6000
4000
4000
2000
2000
0
0
2000
4000
6000
Y(m)
8000 10000 12000 14000 16000 18000 20000
0
0
2000
Simulation No.3 (Line spacing is 1.2km)
4000
6000
Y(m)
8000 10000 12000 14000 16000 18000 20000
Simulation No.4 (Line spacing is 1.93km)
Figure 8: The comparison of simulated map and known map for simulations No.1 to No.4 (survey line direction
is the total gradient)
X(m)
X(m)
10000
10000
8000
8000
6000
6000
4000
4000
2000
2000
0
0
2000
4000
6000
Y(m)
8000 10000 12000 14000 16000 18000 20000
0
0
Simulation No.5 (Line direction is the total gradient)
4000
6000
Y(m)
8000 10000 12000 14000 16000 18000 20000
Simulation No.6 (Line direction is the Axis X)
X(m)
X(m)
10000
10000
8000
8000
6000
6000
4000
4000
2000
2000
0
0
2000
Y(m)
2000
4000
6000
Y(m)
0
0
8000 10000 12000 14000 16000 18000 20000
Simulation No.7 (Line direction is the Axis Y)
2000
4000
6000
8000 10000 12000 14000 16000 18000 20000
Simulation No.8
(Line direction is Perpendicular to total gradient)
Figure 9: The comparison of simulated map and known map for simulations No.5 to No.8
(survey line spacing is 1km)
X(m)
X(m)
10000
10000
8000
8000
6000
6000
4000
4000
2000
2000
0
0
Y(m)
2000
4000
6000
0
0
8000 10000 12000 14000 16000 18000 20000
Simulation No.9 (Line direction is the total gradient)
2000
4000
6000
Y(m)
8000 10000 12000 14000 16000 18000 20000
Simulation No.10 (Line direction is the Axis X)
Figure 10: The comparison of simulated map and known map for simulations No.9 to No.12
(survey line spacing is 1km)
40
INTERNATIONAL HYDROGRAPHIC REVIEW
MAY 2014
magnetic anomaly map in different survey line
directions and the known magnetic anomaly map
can be detected. For results of simulations No. 6 –
No. 12, when the survey line spacing is less than
1km, the variation of the interpolation precision in
the different survey line direction is 0.74~2.03.
When the simulated magnetic anomaly map and
the known magnetic anomaly map is coincident,
little discrepancy between the contours can be
detected in a few areas. However, the variation of
interpolation precision in different survey line
directions range from 0.74 to 2.03. When the
survey line spacing is more than 2km, the larger
discrepancy will be found between the simulated
map and the known map, and the distortion is
distinct.
As shown in Figure 8 (corresponding to simulations No.1 - No.4), if the survey line direction is
fixed (the total gradient direction has been
adopted), the discrepancy between the simulated
magnetic anomaly map with different survey line
spacing and the known magnetic anomaly map
can be detected. There is better agreement
between the simulated map and the known map
(only few magnetic anomalies have been lost), if
the survey line spacing is less than 1.2km
(MI=1nT). The worst difference will be found in
simulation No.4, when the survey line spacing is
more than 1.9km. Although the general trend of the
magnetic anomaly can be approximately
determined, distortion exists in the magnetic anomaly map. This distortion is relative and can be
detected if the discrepancy is more than 2nT for a
contour interval of 10nT, which is 1/5 of the
contour interval in this paper.
Comparing the magnetic anomaly maps of the
simulations No.1 to No. 12, the interpolation
precision creates consistent magnetic anomaly
maps. The higher the interpolation precision, the
smaller the distortion is detected and the agreement improves.
As shown in Figure 9 (corresponding to simulation
No.5 - No.8) and Figure 10 (corresponding to
simulation No.9 - No.12), if the survey line spacing
is fixed, the discrepancy between the simulated
X(m)
10000
X(m)
10000
8000
8000
6000
6000
4000
4000
2000
2000
0
0
2000
4000
6000
Y(m)
8000 10000 12000 14000 16000 18000 20000
0
0
Simulation No.13 (Line direction is the total gradient)
X(m)
10000
4000
6000
8000 10000 12000 14000 16000 18000 20000
Y(m)
Simulation No.14 (Line direction is the Axis X)
X(m)
10000
8000
8000
6000
6000
4000
4000
2000
2000
0
0
2000
2000
4000
6000
8000 10000 12000 14000 16000 18000 20000
Y(m)
0
0
Simulation No.15 (Line direction is the total gradient)
2000
4000
6000
Y(m)
8000 10000 12000 14000 16000 18000 20000
Simulation No.16 (Line direction is the Axis X)
Figure 11: The comparison of simulated map and known map for simulation No.13 to No.16 (interpolation
precision is less than 1nT)
41
INTERNATIONAL HYDROGRAPHIC REVIEW
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X(m)
10000
X(m)
10000
8000
8000
6000
6000
4000
4000
2000
2000
0
0
2000
4000
6000
Y(m)
8000 10000 12000 14000 16000 18000 20000
0
0
Simulation No.17 (Line direction is the total gradient)
4000
6000
Y(m)
8000 10000 12000 14000 16000 18000 20000
Simulation No.18 (Line direction is the Axis X)
X(m)
X(m)
10000
10000
8000
8000
6000
6000
4000
4000
2000
0
0
2000
2000
2000
4000
6000
Y(m)
8000 10000 12000 14000 16000 18000 20000
Simulation No.19 (Line direction is the total gradient)
0
0
2000
4000
6000
Y(m)
8000 10000 12000 14000 16000 18000 20000
Simulation No.20 (Line direction is the Axis X)
Figure 12: The comparison of simulated map and known map for simulation No.17 to No.20 (interpolation
precision is less than 2nT)
Results of the simulations No.13 to No. 20 are
analyzed, and the matching characteristics of the
survey line direction and the survey line spacing
discussed. As Shown in Figure 11 (corresponding
to simulations No.13 to No.16) and despite the
survey line spacing and survey line directions being different, the interpolation precisions are almost
the same, and the simulated and known maps are
coincident. For example, the interpolation precision
where the survey line spacing is 1.2km in total gradient direction and 0.6km perpendicular of the total
gradient direction are equal (1nT). Line numbers
along the latter will be twice the former. The same
result is in simulation No.17 to No.20 (as shown in
Figure 14). To obtain the interpolation precision of
2nT, the survey line spacing is 1.9km in total gradient and 0.8km perpendicular of the total gradient.
The line numbers will be doubled.
3.4 Influence of survey line layout on interpolation precision and magnetic anomaly map (with
observation noise)
In survey practice, observation errors inevitably
exist. To simulate closer to the real survey
practice, the observation error of normal distribution have been added in the representative simulations above and simulation scheme are listed in
Table 7.
Table 7: Simulation scheme with observation noise
So the maximum line spacing along a certain
survey line direction will meet the requirement of
interpolation precision. Line numbers are minimized when survey lines are designed along the
total gradient.
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INTERNATIONAL HYDROGRAPHIC REVIEW
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The simulation aims of Table 7 are described
below. With the observation noise added: (1) The
consistency of interpolation precision and magnetic
anomaly map is verified; and (2) the law of
propagation of errors have been validated for the
interpolation precision. The detailed simulation
results have been listed in Table 8 and Figure 13
and 14.
Table 8: The interpolation precisions in different survey line layouts of simulation background B
(With the observation noise)
Survey line direction
No.
Noise
magnitude
Survey line
spacing
Total gradient
Axis X
Perpendicular of
total gradient
Axis Y
mt
mR
mI
mt
mR
mI
mt
mR
mI
mt
mR
mI
0.5km
1.24
0.98
0.76
1.37
0.98
0.96
1.40
1.01
0.97
1.47
1.02
1.06
1.0km
1.27
1.00
0.78
1.40
1.00
0.98
1.53
1.00
1.16
2.35
0.99
2.13
23
1.5km
1.70
1.02
1.36
2.01
0.99
1.74
2.51
0.99
2.31
3.72
1.00
3.58
24
2.0km
2.41
1.00
2.20
3.19
1.02
3.02
5.19
0.99
5.10
5.89
1.00
5.80
25
0.5km
1.74
1.40
1.03
1.75
1.41
1.04
1.76
1.41
1.05
1.83
1.41
1.18
1.0km
1.76
1.39
1.07
1.79
1.38
1.15
2.02
1.41
1.45
2.53
1.40
2.11
27
1.5km
1.97
1.39
1.40
2.22
1.42
1.70
2.85
1.40
2.48
4.91
1.41
4.70
28
2.0km
2.78
1.42
2.39
3.49
1.42
3.18
4.59
1.42
4.36
5.96
1.41
5.79
21
22
1.0nT
26
1.4nT
X(m)
10000
X(m)
10000
8000
8000
6000
6000
4000
4000
2000
2000
0
0
2000
4000
6000
Y(m)
8000 10000 12000 14000 16000 18000 20000
0
0
Simulation No.21 (Line spacing is 0.5km)
X(m)
4000
6000
Y(m)
8000 10000 12000 14000 16000 18000 20000
Simulation No.22 (Line spacing is 1 km)
X(m)
10000
10000
8000
8000
6000
6000
4000
4000
2000
0
0
2000
2000
2000
4000
6000
Y(m)
8000 10000 12000 14000 16000 18000 20000
0
0
Simulation No.23 (Line spacing is 1.5km)
2000
4000
6000
Y(m)
8000 10000 12000 14000 16000 18000 20000
Simulation No.24 (Line spacing is 2.0km)
Figure 13: The comparison of simulated map and known map for simulation No.21 to No.24
(the observation noise is 1nT, line direction is total gradient)
43
INTERNATIONAL HYDROGRAPHIC REVIEW
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X(m)
10000
X(m)
10000
8000
8000
6000
6000
4000
4000
2000
2000
0
0
2000
4000
6000
Y(m)
8000 10000 12000 14000 16000 18000 20000
0
0
2000
Simulation No.25 (Line spacing is 0.5km)
6000
Y(m)
8000 10000 12000 14000 16000 18000 20000
Simulation No.26 (Line spacing is 1 km)
X(m)
10000
X(m)
10000
8000
8000
6000
6000
4000
4000
2000
2000
0
0
4000
2000
4000
6000
Y(m)
8000 10000 12000 14000 16000 18000 20000
0
0
2000
Simulation No.27 (Line spacing is 1.5km)
4000
6000
Y(m)
8000 10000 12000 14000 16000 18000 20000
Simulation No.28 (Line spacing is 2.0km)
Figure 14: The comparison of simulated map and known map for simulation No.21 to No.24
(the observation noise is 1.44nT, line direction is total gradient)
to obtain the interpolation precision of 1nT, the
survey line spacing must be less than 1km with
observation noise of 1nT and 1.4nT.
In Table 8, mt , can be calculated by the difference
of the reference points between the interpolated
value and the observed value with observation
noise. mR can be calculated by cross points of the
main lines and the reference lines with observation
noise. mI can be calculated by the difference of the
reference points between the interpolated value by
the main lines with the observation noise and the
observed value in the reference lines without the
observation noise.
The interpolation precision of magnetic anomaly（ nT）
2.4
The law of propagation of errors (See formulae (2))
has been verified by the numerical values in
Table 9.
A comparison of the interpolation precision, with
and without observation noise added, is shown in
Figure 15.
2.2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.5
As shown in Figure 15 and Table 8, the obvious
differences can be detected in the interpolation
precision of different survey line layouts between
the survey line spacing and observation noise.
Meanwhile the agreement between the magnetic
anomaly maps can be perfectly reflected by the
corresponding interpolation precision. By increasing the observation noise to obtain the same
interpolation precision, the corresponding survey
line spacing must be decreased. For example, if
survey lines are designed along the total gradient,
The nosie is 1nT
The noise is 2nT
without noise
2
0.7
0.9
1.1
1.3
1.5
1.7
1.9
2
The ling spacing(km)
Figure 15: The comparison map of the interpolation
precision with and without observation noise
4.
THE SURVEY LINE DESIGN METHOD
Based on the analysis above, we can conclude
that the interpolation precision can be applied in
the evaluation of the rationality of the survey line
layout. Further, it can be used to optimize the
survey line layout for marine magnetic surveys.
44
INTERNATIONAL HYDROGRAPHIC REVIEW
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survey lines for marine magnetic surveys can be
programmed. This can be applied in practical
survey conduct and marine magnetic survey
outcomes can be improved.
The rule of survey line layout is to control blank
areas between the survey lines and then adjust the
interpolation precision and survey precision to
meet the total requirements of the magnetic
anomaly map precision. Therefore, the rational
survey line direction must be selected first based
on the priori-magnetic information of survey area,
then control and adjust the survey line spacing to
match the interpolation precision between survey
lines and survey precision.
4.1 Determination of survey line direction
The main requirement in the determination of
survey line direction is to accurately ascertain the
total gradient of the magnetic anomaly of the
survey area. So the priori-magnetic anomaly map
must be digitized for gridding data. For the
non-observed area, the known magnetic anomaly
map can be obtained by using a regional magnetic
field model. The gradient of each point can be
calculated using gridded data, and the total
gradient of the whole survey area can be
calculated.
If the obtained total gradient direction is close to
the axis X (north to south) or the axis Y (east to
west), the axis can be selected as the survey line
direction to simplify the survey practice.
4.2 Determination of survey line spacing
When the survey line direction has been
determined, we can design the survey line spacing
according to the flow chart shown as in Figure 16.
In the technical design of a marine magnetic
survey, the priori-magnetic information of survey
area must be fully known and the rational preliminary survey can be brought forward. Further
optimization of the survey line layout can be given
based on the new magnetic information obtained
by the preliminary survey. The magnetic anomaly
map which satisfied the prearranged survey
precision can be obtained with the optimized
survey line layout and the highest survey efficiency
can be assured.
Figure 16: The flow chart of the survey line layout
5.
Compared to the new survey line layout, the
practical magnetic field has not been considered in
the traditional survey layout (shown in Table 1).
The optimization of the survey line layout in a step
by step process has been embodied by the
method discussed in this paper.
CONCLUSIONS
The design of the survey line layout has been
thoroughly and systematically studied. The evaluation methods of survey line layout have been
described and the influence of survey line layout
have been simulated and discussed. Finally, a new
design method for survey line layout has been
described. Based on the study of this paper, we
can conclude that:
The complexity and the difficulty of the survey line
layout will be certainly increased. Using modern
computing and specialist software, the design of
45
INTERNATIONAL HYDROGRAPHIC REVIEW
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(1) The evaluation method of magnetic anomaly
map and interpolation precision between the survey lines can be effectively applied in evaluation of
the rationality of survey line layout.
of Surveying and Mapping, China.
(2) The highest interpolation precision can be obtained if survey lines are designed along the total
gradient. By increasing the survey line spacing, the
difference of the interpolation precision between
different survey line directions will also be increased. However, regard to certain survey line
direction, the interpolation precision will be different, which will decrease with increasing the survey
line spacing.
(3) The value of the interpolation precision and
magnetic anomaly map is consistent in evaluation
of the rationality of survey line layout. The higher
the interpolation precision, the less distortion in the
magnetic anomaly map and the more the agreement will be. Meanwhile the simulation with observation noise shows that the interpolation precision
is in accord with the law of propagation of errors
and the theoretical analysis of the interpolation
precision is inosculated.
BIAN Gang, LIU Yanchun,YU Bo (2008). “The
Evaluation of Interpolation Residual Precision
with Midpoint of Reference Lines in Marine Magnetic Survey”, Journal of Geodesy and Geodynamics, 28(3), pp. 96~99.

E.C. Boumweester adg A.W. Heemink (1993).
“Optimal Line Spacing in Hydrographic Survey”,
International Hydrographic Review, LXX(1), pp.
37~48.

HUANG Motao, ZHAI Guojun, OUYANG Yongzong (2006). “Research On Error Compensation
in Marine Magnetic Survey”, Journal of Geomatics and Information Science of Wuhan University,
31(7), pp. 603~606.

LIANG Kailong and LIU Yanchun (1996). Marine
Gravity and Magnetic Survey, Publishing House

LIU Yanchun and XIAO Fumin (2006).The
conspectus of the Hydrography, Publishing
House of Surveying and Mapping, China.

LIU Yanchun, LI Mingsan, HUANG Motao
(2001). “The Rank-Defect Adjustment Model for
Survey-line Systematic Errors in Marine Survey
Net”, Journal of Geomatics and Information
Science of Wuhan University, 26(3), pp.
533~538.

National Supervisor Bureau for Quality
Technique (1998). The Criteria of Hydrographic
Survey. Chinese criteria press, China.
BIOGRAPHIES OF THE AUTHORS
Dr BIAN Gang has been a lecturer in the Department of Hydrography & Cartography of the Dalian
Naval Academy since 2011. He received his Doctor’s degree in Geodesy and Surveying Engineering Subject in 2008. He worked on the naval training ship fleet from 2009 to 2011 and was appointed
as the navigation officer of training ship SHI
Chang. He is engaged in hydrographic surveying
theory and data processing and has extensive experience in marine magnetic survey practice and
data processing.
Email: [email protected].
Cell phone: +8613387859531
REFERENCES

LIU Yanchun (2004). The Spatial Constructer of
the Marine Sounding and Data Processing,
Publishing House of Surveying and Mapping,
China.
7.
(4) The integral research of the survey line layout
shows that the new method of the survey line layout described is rational and feasible. An optimization of survey line layout in a step by step has
been described, which is in accord with survey
practice.
6.

Professor Dr XIA Wei is the Associate Professor
in the Department of Hydrography & Cartography
of Dalian Naval Academy. He worked in the Naval
Survey Troop from 2001 to 2002 which? where?
he was appointed as the substitute captain of the
survey unit. He has worked as a lecturer in the
Department of Hydrography & Cartography of the
Dalian Naval Academy since 2003 and researched
hydrographic surveying theory and data processing. He received his Doctor’s degree in Geodesy
and Surveying Engineering in 2009. He has extensive experience in multibeam sounding survey
practice and data processing.
Email: [email protected].
Cell phone: +8613998545423
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Dr JIN Shaohua has been a lecturer in the Department of Hydrography & Cartography of the Dalian
Naval Academy since 2006. He worked in the
Naval Survey Troop from 2004 to 2005 and was
appointed as the substitute captain of the survey
unit. He is engaged in hydrographic surveying
theory and data processing. He received his
Doctor’s degree in Geodesy and Surveying
Engineering in 2011. He has extensive experience
in marine magnetic survey practice and data
processing.
Email: [email protected].
Cell phone: +8613840933021
Professor Dr XIAO Fumin is the Associate Professor in the Department of Hydrography & Cartography of the Dalian Naval Academy. He worked in
the Naval Survey Troop from 1989 to1994 which?
where he was appointed as the substitute captain
of the survey unit. He has been a lecturer in the
Department of Hydrography & Cartography of the
Dalian Naval Academy since 1995 and researched
hydrographic surveying theory and data processing. He received his Doctor’s degree in Geodesy
and Surveying Engineering Subject in 2007. He is
currently the Associate Professor of the department and has extensive experience in hydrographic surveying practice and data processing.
Email: [email protected].
Cell phone: +8613842695886
Dr SUN Xinxuan has been a lecturer in the Department of Hydrography & Cartography of the
Dalian Naval Academy since 2005. He worked in
the Naval Survey Troop from 1999 to 2002 where
which? he was appointed as the captain of survey
unit. He is engaged in hydrographic surveying
theory and data processing. He obtained his
Doctor’s degree in Geodesy and Surveying
Engineering Subject in 2009. He has extensive
experience in chart datum transfer theory and
algorithms.
Email: [email protected].
Cell phone: +8618640862069
Dr CUI Yang has been a lecturer in the Department of Hydrography & Cartography of the Dalian
Naval Academy since 2006. She worked in the
Naval Survey Troop from 2004 to 2005 and was
appointed as the substitute captain of the survey
unit. She is engaged in marine geodesy survey
theory and data processing. She obtained her
Doctor’s degree in Geodesy and Surveying
Engineering in 2013. She has extensive experience in marine geodesy survey practice and data
processing.
Email: [email protected].
Cell phone: +8613998435151
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THE AGS 61 “CABO DE HORNOS”
NEW CHILEAN SCIENTIFIC RESEARCH VESSEL
By Fernando Mingram, Captain (Ret.)
Executive Secretary, National Oceanographic Committee –CONA
On the 1st July 2013, a new Chilean Scientific Research Vessel “Cabo de Hornos” initiated her
research activities. Operated by the Chilean Navy, she constitutes a sound change in
modernization, equipment and capabilities with respect to the previous naval oceanographic
vessels and the limited resources that have existed within other national institutions (see
Figure 1).
Figure 1. Cabo de Hornos
1.
ORIGIN OF THE PROJECT
Marine Scientific Research in Chile
Chile is an oceanic country that includes an oceanic islands system, fiords and austral
channels together with the Antarctic Territory. This particularity demands Chile to have in
place a sustainable scientific marine research development, not just to improve knowledge but
to make a responsible use and appropriate management of the natural resources without
affecting the ecosystem.
The history of the marine research in Chile contains several benchmarks in which the Chilean
Navy has had an outstanding participation with its ships and personnel. One of these
benchmarks was the initiative proposed by the Navy to the Government in 1970, to establish a
National Oceanographic Committee (CONA). The formation of this committee constitutes a
pioneer decision worth highlighting. The Committee is chaired by the Director of the Chilean
Navy Hydrographic and Oceanographic Service, in his capacity as the National Authority in
Oceanography. Actually, 29 members - Universities and State Organizations – form the
CONA which has had an active role in its 42 years of existence, having been recognized as
the research and marine science coordination and enhancing reference institution in Chile.
An example of this was the creation, in 1994, of the CIMAR Program (Marine Research
Cruises in Remote Areas). The general objective of this Program is to study with a multidisciplinary vision the oceanographic, marine biodiversity, ocean-atmosphere interaction and
submarine morphology in remote areas, where the marine environment knowledge has a
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strong influence in the sustainable socio-economic development of local communities and the country in
general, through annual cruises. CIMAR constitutes a reference example of integration and cooperation
between the Chilean Navy – through its vessels and SHOA – with universities and research centers,
facilitating the start-up to hundreds of projects, scientific publications, presentations at marine national and
international Science Congresses, together with the support for Pre and Post grade Thesis for Bachelors in
Science and PhDs.
The Need for an Oceanographic Vessel
The shortage of adequate marine research, oceanographic and fishery platforms has been a recurrent
subject in the Chilean marine sciences environment. For a long time, through different documents and
discussions, SHOA and CONA jointly with the national marine scientific community, have expressed the
need to have an oceanographic vessel to satisfy national research needs.
In September 1992, the former “Thomas Washington” from Scripps, USA, a vessel of the 1960’s with over a
million nautical miles sailed was received by Chile. With the name AGOR “Vidal Gormaz”, she started her
service in the Chilean Navy with an oceanographic research role until 2010.
Different attempts to obtain better platforms did not progress. Nevertheless, SHOA continued to work on a
project to replace the old “Vidal Gormaz” by another used vessel or through the building of a new platform.
SHOA developed and established the High Level Requirements, a fundamental step in the definition of the
characteristic and capabilities such an eventual platform should have to fulfill the national requirements.
The “Medusa” Project
In May 2007, the Navy’s CNO decided to hand the Project to the Naval Program, Research and Development Directorate, with the name “Medusa” to which the fishery research component was incorporated. On
the 28th December 2007, a contract was signed between the Chilean Navy and ASMAR for the construction
of an Oceanographic Vessel. ASMAR hired SKIPTEKNISK company for the ship’s design based on the
final needs definition; WARTSILA for the development and acquisition of the propulsion system and
KONGSBERG for the acoustic sensors. In July 2008 the shipyard started building the ship in Talcahuano,
Chile.
In February 2010, with the vessel ready for her launching and baptism, an 8.8 Richter scale earthquake and
related tsunami affected Talcahuano, causing severe damage to the shipyard and the brand new platform
was left sunken over a sand bank at the end of the dock, after the passage of the tsunami. This extremely
complex event affected the project, the shipyard, the Navy and the country. Insurances were activated and
the recovery of the platform started. After preparatory hard work that took several weeks in the field with
the support of specialized machines, on the 28th January 2011 the MAMMOET, a Netherland company conducted a titanic maneuver to revert the situation and left the vessel afloat and in conditions to repair all
damages and to continue the construction.
2.
AGS 61 “CABO DE HORNOS” – CHARACTERISTICS
She is a 74.1m in length and 15.6m in the beam with a deadweight of 3,000 tons and 35 days of autonomy
without being replenished. With a crew of 9 Officers and 34 enlisted personnel, she can carry up to 25
scientists on board. She has three labs, acoustic and special sensors’ room, 10 and a 40 cubic m freezers
with adjustable temperature ranging from +5°C to -30°C; three jib cranes one of which has a 30 tons type
“A” frame at the stern; three telescopic cranes with a 12 tons capacity, 13 winches for oceanographic,
geology and fishing gears; three multibeam echosounders; a sub bottom profiler, a sound speed profiler, an
Acoustic Doppler Current Profiler (ADCP), multi-frequency sonar for biomass classification; short and long
range omni-directional biomass scan sonar; high precision acoustic positioning sub-system with transponders; monitoring wireless network system, sensors and data synchronization and control sub-system;
submarine telephone UQC, radars and echosounders for navigational purposes and a variety of meteorological instruments that collects data automatically in digital format. It worth highlighting that the vessel
“Cabo de Hornos” is an ultra silent vessel, complying with ICES 209 acoustic standard, that means that she
can sail at a distance of 20 meters from a fish school without being notices by the fishes.
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3.
MAY 2014
THE “CABO DE HORNOS” ACTIVITIES
The first “Cabo de Hornos” mission was the
project “CIMAR Fiordos 19”, which took place
from 01 to 20 July, in the area delimited by the
Reloncaví estuary and the Guafo gulf and
included base line studies to continue the
population of the existing data bases such as
bio-oceanographic processes; primary, bacteria and zooplankton production and sediment
studies in different areas identified as important for the sciences development. Samples
were taken at 17 oceanographic stations in
the area, together with samples of the main
rivers. The activities were conducted by 18
researchers of different universities and 5
specialist of SHOA (see Figure 2).
During August, “Cabo de Hornos” conducted
her first fishery research cruise to evaluate
three different types of hake spawning stock
in the austral oceanic waters. This project was
funded by the Fishery Research Fund and
executed by the Fishery Development
Institute together with two invited researchers
of the Pontifical Catholic University of
Valparaiso, for the gathering of the
oceanographic data (see Figure 3).
Figure 2. Study Area CIMAR Cruise
Figure 3. Fishery research onboard Cabo de Hornos
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She also conducted a large oceanic bathymetric survey as part of the program aimed at completing the
studies required by the Chilean Government to submit its proposal to the United Nations for an extended
Continental Shelf. The planning for 2014 includes over 200 operation days, comprising four oceanographic
cruises, one bathymetric survey and two fishery research cruises (see Figure 4).
Figure 4. Inside the Sonar room
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IC-ENC ENC VALIDATION TRAINING COURSE
By Laura TYZACK (IC-ENC)
& Panagiotis GKIONIS (Hellenic Navy Hydrographic Service)
Abstract
The International Centre for ENCs (IC-ENC) was set up in 2002 with a remit to harmonise the
production and distribution of high quality ENCs. This Note provides an insight into IC-ENC,
its validation processes, and the new ENC Validation Training Course. It is jointly authored by
Lt.Cdr. Panagiotis Gkionis (Hellenic Navy Hydrographic Service, ENC Validation Training
Course delegate) and Miss Laura Tyzack (IC-ENC Data Validator).
Introduction to IC-ENC
IC-ENC is a Regional ENC Coordinating Centre (RENC), established to support the achievement of the IHO’s Worldwide Electronic Navigational Chart Database (WEND) Principles.
IC-ENC is a low cost, not for profit RENC which was set up in 2002. IC-ENC’s role, as an
international centre of ENC excellence, is to assist Hydrographic Offices (HOs) to harmonise
their production and distribution of ENCs. IC-ENC does this by providing four main services to
HOs:
 ENC Production Support
 Independent ENC Validation
 ENC Distribution

ENC Revenue Management
IC-ENC has 12 members of staff across two offices - the headquarters in the United Kingdom
and a regional office in Australia. It has 29 member HOs at present, with new nations joining
on a regular basis. IC-ENC now has a folio of over 5000 ENCs which are validated on a
regular basis. Figure 1 shows the current IC-ENC membership.
Figure 1 – Current IC-ENC membership
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IC-ENC is controlled by its members. The members meet annually through a Steering Committee meeting
to discuss strategic issues, agree on policies and set the budget. There are also Technical and Commercial
Working Groups held each year, attended by both IC-ENC staff and member HOs, which recommend
policies to the Steering Committee.
IC-ENC Validation
IC-ENC’s approach to validation is to consider the impact of any issues, identified during the validation
process, on the end user of the ENC product, the mariner. This is achieved through the use of policies, IHO
documentation, and working practices to assist the IC-ENC Validator in the quality assurance of each ENC
that is produced by the member HOs. The working practices set out the validation procedures, which
include conformance to S-57 and S-58 IHO standards, vertical and horizontal consistency, and assessment
of ENC display on ECDIS. IC-ENC members then receive a comprehensive feedback report for each processed ENC. These reports highlight any data issues including recommendations for improvement. IC-ENC
members have access to the IC-ENC Errors Database, a database of validation tool errors, which explains
each error’s meaning, significance and action to take. This helps the HO to interpret the error and to assist
with their own production and internal validation.
IC-ENC checks an ENC’s data structure against both S-57 and S-58 standards, and also its data content by
making a visual assessment. IC-ENC uses several validation software tools to assist in the validation of
each ENC, including 7Cs Analyzer and Designer, dKart Inspector, and two ECDIS systems. Each validation
software tool generates log files of error messages, which are then inspected and classified according to
IC-ENCs policy regarding the impact to the user. The IC-ENC Errors Database is used by the IC-ENC
Validator to assist the validation process. A sample page is shown in Figure 2.
Figure 2 – Sample page from IC-ENC Errors Database
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Further assessment is made to identify any gaps or overlaps between adjoining cells, and a visual assessment is made of the vertical and horizontal consistency of the ENCs in the area. This is done by accounting
for the purpose of the ENC, voyage routes, prominent navigation features and so on, always with the
navigator in mind. Several examples of these visual assessments are shown in Figures 3-4. Figure 3
shows an example of where a single HO has produced two adjoining cells of the same usage band which
overlap one another. Overlaps or gaps in data can cause serious problems for ECDIS users, so IC-ENC
would ask for immediate action to remove the overlap before it is released for use. Figure 4 shows the two
cells after the overlap has been removed.
Figure 3 – Overlap in data identified using dKart Inspector 6.0
Figure 4 – Resolved overlap
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Figure 5 shows an example of where a single HO has produced two adjacent usage band ENCs, but one
of them is less up-to-date than the other, resulting in misaligned TSS objects. This is a good example of a
problem for which IC-ENC would have asked for an immediate corrective action, given the importance of
TSS objects.
Figure 5 – Misalignment of two Traffic Separation Scheme (TSS) objects
Each ENC is then visually assessed using two widely used ECDIS. The assessment includes checking the
clarity, consistency, application of SCAMIN (density of features when zooming in and out), and general
usability of the ENC. Figure 6 shows an example of where two different HOs have produced neighbouring
ENCs, but the different policies on the use of SCAMIN has resulted in a dataset which is not consistent.
The ENC to the west does not have SCAMIN attributed to the soundings, resulting in a cluttered display in
the shoaler areas, whereas the ENC to the east has a SCAMIN value attributed that is too large, resulting in
the soundings being entirely removed from the display. This is a good example of an issue where IC-ENC
would liaise with the HOs in order to achieve a more consistent display for the mariner, with each HO
receiving individual advice about their implementation of SCAMIN.
Figure 6 – Different implementations of SCAMIN
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Additional checks include the assessment of datums, compilation scales, additional word (.txt) and picture
files (.tif), and CATZOC suitability. If there are any issues for which improvements are possible, the
validator will make an assessment of the impact to the mariner and classify findings accordingly in the
Validation Report. An example of a Validation Report is shown in Figure 7.
Figure 7 – Example P007 Validation Report
Once an ENC has been accepted for release by the producing nation and IC-ENC, IC-ENC makes it available to its Value Added Resellers (VARs). These VAR companies bring together ENCs from a variety of
sources, and have developed commercial services that supply ENCs to users. The VARs therefore manage
this element of the distribution chain, ensuring IC-ENC remains focused on data quality. Eight VARs are
currently appointed (IC-ENC welcomes new applicants), and the variety of competing VAR services
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ensures a high level of customer service. This approach means IC-ENC remains as cost effective as possible. An HO sets its own price for its ENCs, and IC-ENC retains just $1 per annual subscription sold to cover
its operating costs, with the remainder being returned to the HO as part of IC-ENC’s Revenue Management
Service.
IC-ENC ENC Validation Course
The decision was made at the IC-ENC Steering Committee 14 (September 2013), as a capacity building
initiative, to develop an ENC Validation Training Course. This would be available to IC-ENC member HOs
in order to further increase the level of quality amongst members’ ENC production teams. For IC-ENC, this
would involve developing its already present internal training package for new staff members, as the essential components and knowledge base were already in place. It was agreed that the costs of attendance by
the delegates would be met from the central IC-ENC budget. The target date for the pilot course was set for
the first half of 2014. IC-ENC has now completed the pilot training course, which ran from 3rd – 14th March
2014 for three delegates. Figure 8 shows the Course Instructor, IC-ENC Data Manager Mr Mike Hawes,
and the three course delegates.
Figure 8 – Mr Mike Hawes (Course Instructor) with the three course delegates (from left to right):
Mr Hans Wytema, P.Officer Nikoletta Paspaltzi, Lt. Cdr. Panagiotis Gkionis.
The aim of the IC-ENC Validation Training Course is to introduce the delegates to the roles and responsibilities of IC-ENC, with the focus being on the ENC validation process, and to provide them with the knowledge and skills required to carry out internal validations at their home ENC production offices. The objective
of the training course, then, is for each delegate to show the ability to demonstrate an understanding of
ENC validation, including the relevant international standards, content and creation of ENCs, and ENC validation principles and ECDIS performance issues. The training course consists of 10 modules, involving a
variety of both theory and practical based learning exercises, which aim to provide the delegates with the
knowledge and skills required to assess and validate ENC data.
Lt. Cdr. Panagiotis Gkionis, one of the course delegates from the Hellenic Navy Hydrographic Service, has
provided the following review of the IC-ENC Validation Training course:
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“An excellent course, suits from novice to confident validator level. It definitely improved my knowledge of
how IC-ENC deals with ENC data, as well as my ability to use validation tools and better understand
IC-ENC recommended actions for ENC improvement. Instruction was excellent and gave a lot of time to
personal tuition and hands-on training. I would recommend this course to all HOs in need of ENC validation
training for their staff.
During the pilot course, the trainees were introduced to the IC-ENC status, governance and financial framework, its roles and responsibilities, as well as its current and future technology. Basic background information and IHO documentation (including S-57 component documents – ENC Product Specification, Use of
the Object Catalogue for ENC, Object/Attribute Catalogue) related to data validation were presented, before
the whole IC-ENC validation process (IC-ENC, 2013) was theoretically and practically demonstrated.
Initially, the methodology and tools for uploading/downloading of datasets exchanged between IC-ENC and
HOs (Exchange Sets) was described, together with an overview of the applicable data flow/management
scheme.
Then, the trainees were demonstrated the ENC registration procedure and basic checks for data corruption
and non-sequential updates through the IC-ENC in-house developed database and software. A series of
checks according to the S-57 and S-58 (IHO, 2011) standards and specifications were exercised both in the
classroom using dedicated software suites (dKart Inspector, Editor and SevenCs’ Analyzer, Designer,
Optimiser, Manager) as well as at the IC-ENC facilities with cells being actually validated. Variations from
the S-57 and S-58 Standards (errors/warnings) are identified through the IC-ENC Errors Database/Lists
and classified according to the impact to the mariner. Consistency checks of data between ENCs within a
given region were also widely demonstrated. The trainees learnt how to assess data at the boundaries of
adjoining ENCs that have identical compilation scales and to assess data against larger and smaller-scaled
ENCs which overlap it.
The validation procedure continues with the utilisation of two widely used ECDIS to ensure
a safe representation of the chart data for the mariner through a clear, consistent and seamless ENC
display. ECDIS are also used for identification of issues related with the application of the SCAMIN
attribute.
Finally, issues related with ENC data gaps/holes, overlapping data, generalisation, vertex reduction, text
files and .tif files’ display were discussed through case studies. All error/warning messages (per processed
ENC file) produced by the validation software together with any identified issues from the validator’s visual
assessment, consistency and ECDIS checks are compiled in a comprehensive Validation Report which is
sent to each IC-ENC member.”
Future of IC-ENC
IC-ENC will continue to provide a valuable service to its members. IC-ENC is actively seeking to increase
its membership, and thus its ENC coverage, which will bring greater economies of scale to its operations,
and further financial efficiencies. Additionally, following the recent success of the pilot IC-ENC Validation
Training Course, IC-ENC aims to continue to provide further training opportunities to its members, aimed at
improving the understanding of ENC validation.
For more information, please visit the IC-ENC website at www.ic-enc.org.
References
IC-ENC (2013). Explanation of IC-ENC Validation Processes, viewed 24 March 2014, http://www.icenc.org/validation.
International Hydrographic Organisation (2000). Transfer Standard for Digital Hydrographic Data,
viewed 25 March 2014, http://www.iho.int/iho_pubs /IHO_Download.htm.
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International Hydrographic Organisation (2011). Recommended ENC Validation Checks, viewed 25
March 2014, http://www.iho.int/iho_pubs/IHO_Download.htm.
International Hydrographic Organisation (2012). Data Protection Scheme, viewed 25 March 2014, http://
www.iho.int/iho_pubs/IHO_Download.htm.
Biographies of the Authors
Laura TYZACK is a Data Validator for IC-ENC. She joined IC-ENC in July 2013, previously working in a
datafill team within the UKHO since August 2012. She achieved a BSc (Hons) degree in Geography in July
2012 at Bath Spa University. This formed her interest in cartography and the decision to join the UKHO, as
well as become a member of the British Cartographic Society. Aside from cartography, she also has a
strong interest in cultural geography.
Email: [email protected].
Panagiotis GKIONIS has been working for the Hellenic Navy since 1994. Following training at the
Hellenic Naval Academy, he embarked on his seagoing career in 1998. For the next 14 years he found himself within warfare appointments onboard frigates and gunboats, qualifying primarily as a Navigating
Officer. He took up his current appointment as an Assistant Head of the Research and Planning
Department onboard the Hellenic Navy Hydrographic Service (HNHS), following the completion of an
‘MSc Hydrography’ programme in 2012. Following his training at the IC-ENC Validation Training Course, he
is a member of the HNHS data validation team.
Email: [email protected]
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