Cover - Left photo: Trig Cairn MC16, Cue, W.A.; Right photo: Leonora CORS – painted by local
community children.
© Western Australian Land Information Authority, 2015
CONTENTS
INTRODUCTION ....................................................................................................................... 2
SUMMARY OF THE RESULTS ................................................................................................ 3
THE RESULTS IN DETAIL ....................................................................................................... 6
Section 1 - Your use of the existing network of ground marks ............................................... 6
Section 2 - Your use of GNSS .............................................................................................. 15
Section 3 - CORS and the AUSPOS service ....................................................................... 16
Section 4 – Geodetic services .............................................................................................. 21
Section 5 – Datum 2020 ....................................................................................................... 26
Section 6 – Closing comments ............................................................................................. 28
Page 1 of 28
INTRODUCTION
Landgate conducted a geodetic customer questionnaire in mid-2013 to get an update on
users’ current and future needs. Responses were solicited from the Western Australian
surveying and spatial sciences industry through internal contact lists, the Land Surveyors
Licencing Board and the Surveying and Spatial Sciences Institute. The questionnaire was
open from 31 May to 10 July and received 102 responses. This is almost double the number
of responses to the initial 2007 questionnaire upon which this one was modelled.
There were 38 questions on all aspects of the geodetic system and services including the use
of ground marks; the use of Global Navigation Satellite System (GNSS) technology and
Continuously Operating Reference Stations (CORS); delivery of geodetic information and
services; and the proposed new geodetic datum for Australia. Landgate will use the results of
the questionnaire to inform the revision of the Geodetic Strategy 2007-2012.
Over the past 6 years, Landgate has made a significant investment, with additional funding
from the Commonwealth Government through AuScope, in establishing 26 CORS across
Western Australia. At the same time private industry CORS networks have also been
developed in parts of the State to provide real time positioning services to a variety of user
groups. Another major initiative has been the release of the new geoid model for Australia in
2011. This was a vast improvement on the previous model as it provides a better fit with the
Australian Height Datum (AHD) when using GNSS technology. There is, however further work
to be done to realise the benefits of the CORS network through the delivery of a new geodetic
datum for Australia, and also work will continue to improve the geoid model. The other
significant change from the previous questionnaire is that GNSS technology is now the primary
tool for conducting the majority of field surveys.
The questionnaire revealed that:
 Whilst the uptake of GNSS technology is universal, significant value
is placed on ground marks which continue to be used on a regular
basis, and this trend is unlikely to change in the near future.
Surveyors are very conscious of the need to have a physical mark to
validate ‘black box’ technology and provide quality control.
 Whilst accuracy expectations may have relaxed slightly from the
previous survey, over half of the respondents still require accuracies
of 0.025m or better.
 The delivery of geodetic services was rated highly in all aspects.
 The concept of a new datum was generally well accepted.
 About half of the respondents want to participate in an industry
review of the new draft geodetic strategy.
A summary of the results, plus the detailed responses to the questionnaire follow.
Page 2 of 28
SUMMARY OF THE RESULTS
The questionnaire was conducted as part of the development of the Landgate Geodetic
Strategy for Western Australia to 2020. As this new geodetic strategy will be used to guide
investment to 2020, it is important to hear from the users of both the network and Landgate’s
Geodetic services to understand how the system should look in the future.
Landgate received 102 responses to the questionnaire however the most responses received
for any one question was 93. There was a good spread of different industry sectors - State
and Local Government, plus small, medium and large surveying companies. All state
geographic regions - metro, major urban centres, rural and remote were represented.
Section 1 - Your use of the existing network of ground
marks (Questions 1-16)
This section provided a useful insight into the type of surveys being conducted and accuracy
requirements, how often the marks are being used and their fitness for purpose.
Types of surveys: Respondents were polled on the type of surveys they conduct that use
the geodetic network and their associated accuracy requirements. Horizontal accuracy
requirements ranged from 0.001m for geodetic, civil engineering and construction up to 1m for
mapping projects. Over 50% of users require horizontal accuracies of 0.025m or better.
This has relaxed slightly from the 2007 survey where almost 70% required this accuracy
range. The vertical accuracy requirements had the same range – 0.001m to 1.0m and 60% of
users require vertical accuracies of 0.025m or better. Likewise this is slightly less than the
75% in the 2007 questionnaire. The question of accuracy is quite arbitrary as it depends on
individual project requirements and location, however it does provide a good understanding of
the broad user needs.
Ground mark usage: Almost 70% of respondents use the network either daily or
weekly and would use between 1 and 20 marks per month. Users found that marks were
readily available, however they estimate that between 10% and 25% of these marks are either
not fit for purpose (eg obstruction of GNSS signals) or have been damaged or destroyed.
Most respondents stated that the network density was adequate. However, where this
was not the case they would establish supplementary ground control marks based on the
geodetic network to support their projects. Ground marks that deliver AHD71 heights are
still very important to surveyors and engineers as they frequently use spirit levelling to
establish and propagate heights. Throughout this section comments were invited and these
provide a useful insight into specific issues such as mark suitability and density as well as how
the network is being used by industry and suggestions for improvements.
Section 2 - Your use of GNSS (Questions 17-19)
Adoption of GNSS: There is now widespread adoption of GNSS surveying with Real Time
Kinematic (RTK) being the most popular technique. However there is an expanding practice
that takes advantage of more government and private industry CORS as they become
Page 3 of 28
available (Network RTK, AUSPOS, Differential Global Positioning Systems (DGPS) and
Precise Point Positioning (PPP)) with at least 30% of respondents adopting CORS based
positioning techniques. Even with the uptake of new technology only 4% of respondents
have reduced their reliance on ground marks, whilst 91% have either increased or
maintained their reliance on ground marks.
Section 3 - CORS and the AUSPOS service (Questions 20-27)
CORS benefits: The fast, accurate and free AUSPOS online positioning service from
Geoscience Australia (GA) is reliant on the Landgate CORS network in WA. This post
processing service enables users to submit their observed GNSS data which is processed in
conjunction with local and national CORS sites to provide very accurate site coordinates. The
majority expectation is a position solution with an accuracy of better than 0.02m from
1-3 hours of observations delivered within one day. This is achievable in the south west of
the State where the CORS network is denser, however 6 hours of observation is required for
the remainder of the State where the CORS network is sparse. When asked if Landgate
should either invest in more CORS, invest in more ground marks or both, 60% of
respondents believe there should be a continuing investment in both CORS and ground
mark infrastructure with 26% suggesting more ground marks only.
CORS in the future: A 2013 National Positioning Infrastructure (NPI) Plan complied by the
Australian government, in consultation with State/Territory Governments and industry,
articulates a vision for a national network of CORS stations and a processing infrastructure to
enable the delivery of at least 0.05m real time positioning service across Australia. Based on
this concept, users were asked if they would subscribe to this type of service. 40% of users
would subscribe to a future real-time positioning service that offers 0.05m accuracy
(44% are undecided). Users were then asked if their use of ground marks would reduce as a
result of this service. More than 50% of users stated that the described NPI would not
reduce their reliance on ground marks. In addition, 44 respondents added comments
relating to the proposed NPI service with half of the comments relating to the continuing need
for ground marks for quality control. Other comments related to the potential coverage and
service delivery and that the accuracy would not be good enough for their requirements.
Section 4 – Geodetic services (Questions 28-34)
Online service delivery: Our online delivery of geodetic mark information was rated
highly with 86% selecting either very good or good. This is surprising given the ongoing
compatibility issues with the Survey Channel Map Viewer which is the primary mechanism for
customers to access geodetic mark information.
When asked to suggest improvements, most comment was centred on information delivery
through mobile devices and the inclusion of photos on station summaries. In 2015 geodetic
information will be available on mobile devices through a Landgate Innovation sponsored
project.
Calibration services: Responses to questions related to Landgate calibration facilities
and services showed that collectively 96% of users of the Landgate calibration services
provided a positive rating. For the Barcode staff calibration facility the number of users was
Page 4 of 28
36% of respondents, and of those who rated the service 97% gave a positive rating.
The number of users of the GNSS test facility was 44% of respondents and of those 92%
provided a positive rating. About 80% of respondents indicated they use the Electronic
Distance Measurement (EDM) Calibration facilities and service and 99% gave it a positive
rating. There is a requirement to calibrate EDMs under the Licenced Surveyors Regulations
1961 but facilities are only available at Bentley, Kalgoorlie and Busselton. When asked if more
regionally located EDM calibration ranges were required 53% of interested respondents
answered yes with the most popular location being the Pilbara.
Participants were also given an opportunity to provide comments on any of the calibration
facilities and services. These ranged from the difficulties of undertaking EDM calibrations
when having to travel from regional centres, to issues with the EDM Calibration software
(which have now been resolved) and a suggestion to identify geodetic marks that would be
suitable for GNSS testing.
Section 5 – Datum 2020 (Question 35)
Datum modernisation: The final section of the questionnaire covered the concept of a
new geodetic datum for Australia which is proposed to be implemented over the next two
years. Participants were provided with some background information about the proposed new
datum and were then asked if they felt it would have a serious impact on their business
processes. More than half of the respondents confirmed the new datum would not
adversely affect their business. Only 26% said they would be impacted and the remainder
were undecided. Many provided comments on various issues with many stating that the small
shift of approximately 1.8 metres would make it difficult to identify which datum a coordinate
was associated with. Many also commented that the change would be a good initiative.
Section 6 – Closing comments (Questions 36-37)
Participants were given an opportunity to provide additional comments or feedback and these
were wide ranging from concerns about the datum, positional accuracies and standards.
There were no comments that were critical of Landgate. Complimentary comments included:
“Things generally seem to be heading on the right track, although I get the
impression that a lack of funding for Landgate is having a serious impact
on the whole surveying structure in WA.”
“The state geodetic network has been appropriate to the technology up till
now. With increasing expectation for positional certainty, upgrading to
keep in touch with development in technology is essential.”
“As an ‘older generation’ surveyor I've probably witnessed more of the
changes in the geodetic network than most current practising surveyors. I
think Landgate is responding well to the demands of industry.”
The final question asked if participants would like to be part of the industry review of the draft
geodetic strategy. 39 respondents nominated to be reviewers of the draft geodetic
strategy.
Page 5 of 28
THE RESULTS IN DETAIL
To show the representation of the different sectors the 102 responses have been categorised:
Sector
Response Count
Large Survey Company
30
Medium Survey Company
27
Small Survey Company
28
Mining
2
State Government
8
Local Government
4
Academia
3
Total
102
Whilst there were 102 responses, the most responses for any one question was 93. The
apparent under-representation of mining is because most mining companies generally
contract out their surveying work. Note also that some responses are from different employees
of the same company or agency. It is appropriate to include all responses as they may be
operating in a different sector within the company.
Section 1 - Your use of the existing network of ground
marks
Question 1 - When you use the geodetic network, what would be your horizontal
accuracy requirement? This question gives an indication of the types of surveys being
conducted and the accuracy requirements for horizontal coordinates.
Answer Options
Response
Percent
Response
Count
Cadastral Surveys
76%
68
Ranged from 0.002m to 0.30m with most
requiring between 0.01m and 0.025m
Geodetic Surveys
69%
61
Ranged from 0.001m to 1.0m with most
requiring between 0.005m and 0.02m
Civil Engineering
73%
65
Ranged from 0.001m to 0.10m with most
requiring between 0.005m and 0.02m
Construction
73%
65
Ranged from 0.001m to 1.0m with most
requiring between 0.005m and 0.02m
Mining
52%
46
Ranged from 0.005m to 1.0m with most
requiring between 0.05m and 0.10m
Environmental Studies
44%
39
Ranged from 0.01m to 5.0m with half
requiring 0.10m
Mapping
52%
46
Ranged from 0.005m to 10.0m with most
requiring between 0.02m and 0.10m
Other (please specify)
3%
3
Ranged from 0.002m to 0.20m
answered question
Horizontal Accuracy Requirement
89
Note that participants could select multiple types of survey, and the percentage is based on
the total number of respondents.
Page 6 of 28
Types of Surveys Using the Geodetic Marks ‐ Horizontal
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Question 2 - When you use the geodetic network, what would be your vertical accuracy
requirement? This question gives an indication of the types of surveys being conducted and
the accuracy requirements for heights.
Answer Options
Response
Percent
Response
Count
Cadastral Surveys
67%
58
Ranged from 0.001m to 1.0m with most
requiring between 0.01m and 0.10m
Geodetic Surveys
68%
59
Ranged from 0.001m to 0.50m with most
requiring between 0.005m and 0.02m
Civil Engineering
76%
66
Ranged from 0.001m to 0.50m with most
requiring between 0.005m and 0.02m
Construction
77%
67
Ranged from 0.001m to 0.10m with most
requiring between 0.005m and 0.02m
Mining
49%
43
Ranged from 0.005m to 2.0m with most
requiring between 0.005m and 0.02m
Environmental Studies
44%
38
Ranged from 0.005m to 1.0m with most
requiring between 0.01m and 0.10m
Mapping
47%
41
Ranged from 0.005m to 1.0m with most
requiring between 0.02m and 0.10m
Other (please specify)
6%
5
Ranged from 0.005m to 0.1m
Vertical Accuracy Requirement
87
answered question
Note that participants could select multiple types of survey, and the percentage is based on
the total number of respondents.
Page 7 of 28
Types of Surveys Using the Geodetic Marks ‐ Vertical
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Other requirements for questions 1 and 2 included gravity, historical and control surveys.
Overall Accuracy Requirements
Horizontal Positioning
Accuracy Requirement
Vertical Positioning
Percentage of Users
Accuracy Requirement
Percentage of Users
≤ 0.01m
36%
≤ 0.01m
46%
0.015m - 0.025m
20%
0.015m - 0.025m
14%
0.030m - 0.050m
21%
0.030m - 0.050m
18%
0.08m - 0.10m
16%
0.06m - 0.10m
16%
0.15m - 0.50m
5%
0.15m - 0.50m
4%
>0.5m
2%
>0.5m
3%
Question 3 – How often do you use the geodetic network?
Response
Percent
Response
Count
Daily
12%
11
Weekly
57%
53
Monthly
27%
25
Rarely
4%
4
Answer Options
4%
12%
27%
57%
Daily
Weekly
Monthly
Rarely
93
answered question
Page 8 of 28
Question 4 - How many marks do you use per month?
Response
Percent
Response
Count
0-5 marks
48%
45
6-20 marks
45%
42
21-50 marks
4%
4
>50 marks
2%
2
Answer Options
4%
2%
0‐5 marks
48%
6‐20 marks
21‐50 marks
45%
>50 marks
93
answered question
Question 5 - Where do you conduct most surveys which use the geodetic network?
Response
Percent
Response
Count
Metro area
46%
43
Major Urban
Centres
14%
13
Rural
29%
27
Remote
11%
10
Answer Options
answered question
11%
Metro area
46%
29%
14%
Major urban
centres
Rural
Remote
93
Question 6 - Select one or more of these regions in which you conduct surveys using
the geodetic network.
70%
60%
50%
40%
30%
20%
10%
0%
As participants could select more than one region, the percentages are based on the number
of respondents (93).
Page 9 of 28
Question 7 - For surveys requiring accurate GDA94 coordinates, how frequently are
geodetic survey marks available when required?
Response
Percent
Response
Count
Always (>90%)
34%
32
Usually (>75%)
56%
52
Sometimes (>50%)
9%
8
Rarely (<25%)
1%
1
Never
0%
0
Answer Options
1% 0%
Always (>90%)
9%
34%
Usually (>75%)
Sometimes
(>50%)
Rarely (<25%)
56%
93
answered question
Question 8 - For surveys requiring accurate AHD heights, how frequently are geodetic
survey marks available when required?
Response
Percent
Response
Count
Always (>90%)
25%
23
Usually (>75%)
57%
52
Sometimes (>50%)
17%
16
Rarely (<25%)
0%
0
Never
1%
1
Answer Options
0%
17%
1%
Always (>90%)
25%
Usually (>75%)
Sometimes
(>50%)
Rarely (<25%)
57%
Never
92
answered question
Question 9 - How many marks do you visit that are not fit for your purpose, i.e.
obstructed for GPS surveys, unable to locate, damaged or destroyed?
Response
Percent
Response
Count
Hardly any (<10%)
24%
22
Some (10-25%)
58%
54
A lot (>25%)
16%
15
Too many (>50%)
2%
2
Answer Options
answered question
2%
16%
24%
Hardly any
(<10%)
Some (10‐25%)
A lot (>25%)
58%
Too many
(>50%)
93
Comments 




Benchmarks are graded out in large numbers in rural areas by Local
Authorities and their contractors
Older generation SSM's didn't always provide for development and
vegetation growth, or had not been well placed for access
Many destroyed & not replaced.
A lot of SSM's in rural areas with low accuracy heights
Generally don't have the height accuracy required
Page 10 of 28

Would prefer the relocating of Trig's to roadways as many are difficult
to access through farmers paddocks and some tree covered.
Destroyed or tree cover
Our region is fortunate to have low vegetation cover
Typically trees, destroyed, and missing RMs through road resurfacing
Most are obstructed by trees for GPS observations
Lots of trees obstructing GPS use
Trees would be the most common obstruction, damaged or destroyed
not very common <5%
Many line of sight SSMs are under trees
Some have obstacles obscuring GPS accuracy
Depends how remotely from Port Hedland we are working.
Alleviate most risk by investigating aerials before going to site
We usually look at mark statuses to avoid destroyed marks
So far so good!












Question 10 - For surveys requiring accurate GDA94 coordinates, is the current density
of geodetic survey marks suitable for the surveying techniques/technology you
currently use?
Response
Percent
Response
Count
Always (>90%)
19%
18
Usually (>75%)
60%
56
Sometimes (>50%)
18%
17
Rarely (<25%)
1%
1
Never
1%
1
Answer Options
answered question
1%
18%
1%
Always (>90%)
19%
Usually (>75%)
Sometimes
(>50%)
Rarely (<25%)
60%
Never
93
Comments 







Sometimes we have to put our own mark in on the beach to get the base
station with a clear view of the survey area (could use better comms!)
We mainly use GPS with a 4.5km range and have few problems.
Needs densification and updating in certain areas
We operate predominantly in rural areas where marks are not always
available; when working in larger towns or regional cities there are usually
suitable marks that we can access
If not I use AUSPOS
Could convert some more control in SSA areas to SSM accuracy levels
Can usually find a point in remote areas to then use to set up our own
control points at our work sites
RTK Survey of Mining tenements usually require the establishment of a
base station near the project
Page 11 of 28
Question 11 - For surveys requiring accurate AHD71 heights, is the current density of
geodetic survey marks suitable for the surveying techniques/technology you currently
use?
Response
Percent
Response
Count
Always (>90%)
12%
11
Usually (>75%)
58%
54
Sometimes (>50%)
26%
24
Rarely (<25%)
2%
2
Never
2%
2
Answer Options
2%
2%
Always (>90%)
12%
Usually (>75%)
26%
Sometimes
(>50%)
Rarely (<25%)
58%
Never
93
answered question
Comments –





Some areas are very deficient
Needs densification and updating
There appears to be a lack of maintenance of the geodetic marks in the
areas where we operate & we find that there may be unstable ground or
soil conditions affecting the reliability of the marks and their reference
marks
For accurate height surveys we use dumpy levels generally involves
traversing up to a couple of kilometres
In the coastal zone the key word is "accurate" AHD.
If not I use AUSPOS

Could convert some more control in SSA areas to SSM accuracy levels

Can usually find a point in remote areas to then use to set up our own
control points at our work sites

Question 12 - For surveys requiring accurate GDA94 coordinates, do you establish your
own geodetic control marks for your projects?
Response
Percent
Response
Count
Always (>90%)
22%
20
Usually (>75%)
36%
33
Sometimes (>50%)
30%
28
Rarely (<25%)
9%
8
Never
4%
4
Answer Options
answered question
4%
9%
Always (>90%)
22%
30%
36%
Usually (>75%)
Sometimes
(>50%)
Rarely (<25%)
Never
93
Comments 





Base station we use needs clear view of the water we are surveying.
For GPS base security and convenience
New marks are based upon existing geodetic control
SSA control
On site to avoid theft of equipment and future accessibility
Usually work in a local grid
Page 12 of 28
Question 13 - For surveys requiring accurate AHD71 heights, do you establish your
own geodetic/control marks for your projects?
Response
Percent
Response
Count
Always (>90%)
32%
30
Usually (>75%)
41%
38
Sometimes (>50%)
14%
13
Rarely (<25%)
7%
6
Never
7%
6
Answer Options
7%
7%
Always (>90%)
32%
14%
Usually (>75%)
Sometimes
(>50%)
Rarely (<25%)
41%
Never
93
answered question
Comments –



AHD71 values determined from existing control
Always in conjunction with GDA coordinates
I come off SSM data to establish my own
Question 14 - How important is accurate AHD71 height to your survey operations?
Response
Percent
Response
Count
Very Important
86%
80
Not Critical
14%
13
Answer Options
Very Important
Not critical
86%
14%
93
answered question
Question 15 - How do you establish AHD71 heights?
Response
Percent
Response
Count
Spirit Levelling
55%
61
Total Station
11%
12
GPS and
AUSGeoid09
23%
25
All Three Methods
12%
13
Answer Options
Spirit Levelling
12%
Total Station
23%
55%
11%
GPS and
AUSGeoid09
All Three
Methods
93
answered question
Other Methods and Comments –






Simultaneous water level transfer from primary AHD site.
All of the above depending upon requirements
Combination parallel plate & Heerbrug flat wooden and total station
depending on project
We sometimes establish AHD71 heights by all of the above, but in critical
areas prefer spirit levelling
Often by RTK with checks
Depending on purpose Spirit Level/Total Station
Page 13 of 28





Depends on job, sometimes GPS, sometimes Total Station
RTK & CORS Network
DGPS and AusGeoid09
Spirit Levelling & Total Station
Depending on distance from a BM we may use GPS if it will most likely
yield better than 12rootK
Question 16 - Do you use ellipsoidal heights and have a use for true GDA94 ellipsoidal
heights (ellipsoidal heights that are not based on AHD + AUSGeoid09, but are
propagated from the GDA94 fiducial marks)?
Response
Percent
Response
Count
Yes
30%
28
Yes
No
70%
65
No
Answer Options
answered question
30%
70%
93
Page 14 of 28
Section 2 - Your use of GNSS
Question 17 - What GNSS/GPS collection modes do you use?
Response
Percent
Response
Count
80%
Network RTK
31%
29
60%
RTK
75%
70
40%
Post Processed
44%
41
20%
AUSPOS
23%
21
0%
DGPS
11%
10
PPP
1%
1
All
13%
12
Answer Options
93
answered question
Note that participants could select multiple options, and percentage is based on the total
number of respondents.
Question 18 - To what extent has your reliance on the physical geodetic network
changed with the adoption of GNSS technology?
Response
Percent
Response
Count
Increased
51%
47
Increased
Reduced
4%
4
Reduced
About the same
40%
37
Don't know
5%
5
Answer Options
5%
40%
About the same
Don't know
4%
93
answered question
51%
Question 19 - Do you expect that your reliance on physical geodetic network will
change over the next 5 years?
Response
Percent
Response
Count
Increase
40%
37
Reduce
4%
4
About the same
53%
49
Don't know
3%
3
Answer Options
answered question
93
3%
Increase
40%
Reduce
About the same
53%
Don't know
4%
Page 15 of 28
Section 3 - CORS and the AUSPOS service
As the Landgate CORS data is used in AUSPOS, the GA’s online GNSS Processing Service,
it is appropriate to get an understanding of user needs and expectations in terms of this
service.
The following background information was provided to participants:
The future geodetic network is increasingly going to
rely on Continuously Operating Reference Stations
(CORS) especially in rural and remote areas where
access to the ground mark network can be
problematic. It will become more cost effective to
establish local control based on CORS rather than
rely on ground marks. In the past 5 years, Landgate
has built 22 CORS across WA and another 4 are
planned in the next 12 months – refer to map. Data
from these sites can be downloaded and used for
post processing and all of these sites are used in the
AUSPOS online processing service provided by
Geoscience Australia. AUSPOS provides users with
the facility to submit data from dual frequency
GNSS receivers to derive accurate coordinates.
With the current network density in the south west of the State users can expect to
achieve accuracies of 1-2cms for GDA94 horizontal coordinates with as little as 2
hours data. The remainder of the State would require a 6 hour occupation to achieve
this accuracy.
Deriving accurate AHD heights from a CORS network is a little more difficult and in
the near term would require connections to known spirit levelled marks.
Question 20 - What horizontal accuracy would you like available from an AUSPOS
service?
Response
Percent
Response
Count
0.010m or less
32%
27
0.020m
48%
41
0.025m - 0.05m
19%
16
0.1m - 0.5m
1%
1
Responses
1%
19%
answered question
48%
0.010m or
less
32%
0.020m
0.025m ‐
0.05m
0.1m ‐ 0.5m
89
Participants could nominate any accuracy and the results have been grouped and aggregated.
Page 16 of 28
Question 21 - What vertical accuracy would you like available from an AUSPOS
service?
Responses
0.010m or less
Response
Percent
Response
Count
22%
19
0.020m
49%
42
0.025m - 0.05m
27%
23
0.1m - 0.5m
2%
2
2%
27%
0.010m or
less
22%
0.020m
0.025m ‐
0.05m
49%
0.1m ‐ 0.5m
89
answered question
Participants could nominate any accuracy and the results have been grouped and aggregated.
Question 22 - For your accuracy requirement, what is the maximum occupancy time
you would consider reasonable for establishing control using AUSPOS?
Response
Percent
Response
Count
<10mins
16%
14
1hr
33%
29
2-3hrs
38%
34
Answer Options
6hrs
14%
14%
16%
<10mins
1hr
38%
33%
2‐3hrs
6hrs
12
89
answered question
Question 23 - For your accuracy requirement and your maximum occupancy time, what
latency would you require for receipt of results - understanding there is a delay in the
AUSPOS service acquiring the precise ephemeris Ultra Rapid - near real time; Rapid next day; Final - 2 weeks?
Response
Percent
Response
Count
<Half hour
16%
14
Same day
38%
34
Same day
Next day
46%
41
Next day
Answer Options
16%
38%
46%
89
answered question
<Half hour
Page 17 of 28
Question 24 - Considering the density of the current CORS network built and planned,
and the AUSPOS accuracies available now, would you rather Landgate?
Response
Percent
Response
Count
Invest in more
CORS
15%
13
Invest in more
ground marks
26%
23
Both
60%
53
Answer Options
15%
Invest in more
CORS
Invest in more
ground marks
Both
26%
60%
89
answered question
Question 25 - If a National Real Time Positioning service offering 5cm horizontal
accuracy becomes available, would you subscribe to this service if it was reasonably
priced?
Response
Percent
Response
Count
Yes
40%
36
No
16%
14
Don't know
44%
39
Answer Options
Yes
40%
No
16%
Don't know
44%
89
answered question
Question 26 - If this was to be introduced would your use of physical ground marks
reduce?
Response
Percent
Response
Count
Yes
19%
17
No
53%
47
No
Don't know
28%
25
Don't know
Answer Options
answered question
Yes
19%
53%
28%
89
Question 27 – Do you have any comments relating to Questions 25 and 26?
Relating to quality control and ground marks:



Geodetic marks are required for QA of positioning systems in the field, and
the determination of calibration and transformation parameters
Physical marks will still be required to validate and QA. We presently
subscribe to the Perth VRS Network.
The physical ground marks are required when the CORS and Real Time
positioning service cannot give a consistent or accurate vertical component.
Generally the horizontal accuracy is consistent enough.
Page 18 of 28




















This probably will always be the case when relying on geoid models. We
currently use two real time positioning services including our own CORS
station offering better than 5cm horizontal accuracy.
The more GPS networks are used the more daily checks will be performed at
various SSM's.
If we were to use the AUSPOS to establish some control I would still need to
check on an established ground mark.
We're using the VRS Network for a lot of our work now and would like to see
an increased use of this in the future but we still like the physical marks in
the area to verify our work and signal is OK
Re: Q26. Local marks would still be used to verify results
We will always use existing ground marks to check the positional
information.
Checking against known physical marks is still necessary to avoid potential
blunders.
Will always need ground marks for redundancy and check measurements
Would still need some ground marks for checking purposes
Checks will always need to be made in the field to ensure signal, datum and
settings are correct.
Also need to check onto existing control to check validity of data supplied via
corrections
You would still need to check on existing marks to confirm the accuracy
achieved in your area of survey.
The biggest thing for me is the vertical accuracy and tying in with historical
data and local marks. You still need to check on local ground marks to have
confidence in your results. Maybe the density of the ground marks could be
relaxed. CORS and the NRTP is definitely the future, but you still need your
localised checks.
Always require a site (point) for gross error checks
Ground marks are still good as a local datum point for surveys that everyone
can use and has access to relate surveys together
As with all surveying it is essential that checks are able to be made to ensure
that the data is correct prior to setting out, thus ground marks or some other
form of check is needed.
Verification
I'd still check onto ground marks
We always need checks & ground marks can be updated from tie ins
You need physical ground marks for checks
Relating to coverage and service:


Really would depend on the cost and the need for that type of accuracy - bit
limited at 5cm. Physical ground marks are going to be required for quite
some time yet. What happens if the satellite codes get scrambled in the
future, for instance in times of war or civil unrest?
We have been involved in discussions instigated by Landgate on this matter
previously. Return on Investment is always a key factor and in our case we
have a local CORS single station operating now. Maybe there is a facility to
integrate these into the "national system" I know we are not alone in having
that sort of infrastructure, and I know speed flow of data is
always a concern to get suitable results but with the NBN rollout that may
improve. Whatever the investment it has to be flexible and capable of updates
as technology improves. More ground marks are not flexible and cognisant of
technological change, and also limited to Surveyor only use. I don’t believe
the market will diminish but rather increase well beyond Surveyor use. As
often happens for better or worse - let other users pay and Surveyors will be
a minority on the side as a benefit to a system. With RTK Netwest and the
Leica systems (and most likely others) already in place it is those systems
that should be utilised and integrated to become truly effective.
Page 19 of 28





It would only become clear how this would work once tested for accuracy,
precision and reliability.
If you had a low volume CORS licence that I could book a $20 per day I
would consider using it! I only need it 1 or 2 days per month
I doubt a national real time service would be economically viable for us as a
lot of our area has limited or no phone coverage and satellite is too
expensive for RTK corrections.
Will be limited by telephone coverage in the remote areas but generally
would be handy over many areas of the state assuming current mobile
towers are maintained and density increased in time.
Depends on the coverage
Relating to accuracy requirements:







Needs to be better than 5cm say at least 2cm
Height accuracy is often more of a problem than horizontal position
5 cm is not accurate enough for many applications.
Would require high vertical accuracy (<0.05m)
I'm assuming that the vertical accuracy would not be good.
5cm horizontal accuracy is not precise enough for the construction of
retaining walls, etc.
5cm accuracy is generally not accurate enough for 99% of survey work where
RTK is possible. Eg Road Pickup, Contour & Feature Surveys, Control
Surveys, Cadastral Connections.
General comments:








It is hard to forecast future work pattern opportunities as we operate over a
wide geographical area that whilst being "rural" also includes many small,
medium and large sized towns. We operate on evaluating each job on a "site
specific" basis depending on what the clients require on any particular job
Due to my Job with the Shire we have built up our own control network in
some areas.
At 68 years old, I am not expecting to continue using the network for many
more years
Ground Marks are likely to be more accessible
Post-processing still no good for site set-out
I do a lot of metro close proximity height work, with infrequent country use.
Would possibly use this service in rural areas where physical ground marks
were widely spaced but probably happy to wait for AUSPOS results in most
cases.
Largely determined by the contract licensed surveyors used
Page 20 of 28
Section 4 – Geodetic services
Question 28 - How do you rate Landgate's online delivery of geodetic mark
information?
Response
Percent
Response
Count
Very good
46%
41
Good
40%
36
Satisfactory
8%
7
Poor
6%
5
Very poor
0%
0
Answer Options
answered question
6% 0%
Very good
8%
46%
Good
Satisfactory
40%
Poor
Very poor
89
Question 29 - Do you have any comments and/or suggestions for future delivery
options e.g. mobile technology access (including survey controllers), photos in station
summaries, customised reports etc.?
Map Viewer:










Map Viewer is very out dated!!!
The website (Map Viewer) is very slow when you zoom into the area
required to ascertain availability of marks
Faster web site
Very, very clunky interface for sourcing geodetic mark information. Have a
look at how the geodetic database in New Zealand operates:
http://apps.linz.govt.nz/gdb/
All of the above but mainly have the geodetic information available
through the New Map Viewer.
Geodetic Mark info is dependent on Map viewer working!
When you access marks through Map Viewer there is no requirement for
an additional password. If you access marks in 'survey' through the menu
there is an additional password required. Why?
Simpler way of retrieving data from Map Viewer would be good.
Please put the Geodetic marks on the NEW Map Viewer. Make it on click
download of a PDF containing the summary and Location Sketch. Update
the sketch to assist with locating marks & RM's! Create a public Google
map of the SSM's state wide for easy location of marks in the field. Make
mark info accessible by smart phone.
A true A4 print of the area being viewed in Map Viewer when searching
cad & geodetic info
Access on mobile devices:






Access using mobile phones or tablets would be distinct advantage,
especially via Android devices.
Delivery of data on the fly using mobile technology while in the field
would be VERY useful
A smart phone app. locating the closest ground points to current location.
Phone app for easy field access
Mobile technology access would be fantastic
Ease of mobile phone access would be of benefit.
Page 21 of 28



Better access through smartphones would be good
Yes, mobile delivery options may be helpful.
Mobile phone access could be very useful
Photos on station summaries:








Photo's would be a waste - the current sketch's, aerial overlays and coords are enough
Access to photos in station summaries is good.
Photos would be fantastic.
Station photos or access photos may be helpful.
Photos would be a good addition in my opinion.
Photos in station summaries is a great idea
Photos probably less so - decent aerial photography usually gives a fair
idea as to whether mark is suitable for GPS base.
Include a sky plot on SSM diagrams showing suitability of station for
GNSS
Other useful information:






Include information on main roads and other control points (provided they
tie in correctly)
When an AHD is adjusted the summary sheet should change year text to
suite eg original = AHD 71, amended = AHD 1982, for example.
Only a minor issue, but if an SSM / BM has been knocked, don't show it as
a green triangle still on Landgate Map Viewer
Data from CORS stations based upon work location to be a selectable
option for delivery
Providing better site descriptions for the ground marks and reference
marks; many were placed in the 1980's and very early 1990's in areas
where many have been damaged and construction activities (particularly
earthworks) have changed the immediate locality
Bring back the good points from old SSM sheets - error ellipses, bold for
primary obs, etc.
Files and formats:




An option to extract the SSM Sketch and Details as one PDF (currently we
create two files, sketch and details and merge them using adobe).
It would be good to report on a selected region and acquire all information
- i.e. summary and sketch in one go so we don’t have to select/download
individual SSM summaries and sketches for a region.
I don’t believe there is a say csv format of the coordinates of a station
available that can be directly downloaded into a computer/data logger (all
the same nowadays) so as to avoid transcription errors. Be good if that
were available. A downloadable shape file layer showing State-wide SSMs would be very
useful for mining exploration companies.
General comments:





With Reg22A, the role of SSMs have become more critical for the
preservation of the cadastre. The need to confirm the reliability of the
coordinates through checks, whether by ground marks or some other
means is a legal requirement.
Landgate requires a more extensive budget for replacing destroyed SSMs
It would be good if you could offer courses for non surveyors on how to
use marks etc. With integration of systems they are being used by more
and more non surveyors. e.g. research and farming
I think the current product is good.
We really only use SSM station summaries which come through fine
Page 22 of 28
Question 30 - How do you rate Landgate's EDM Calibration facilities and
services?
Response
Percent
Response
Count
Very good
28%
19
Good
54%
37
Satisfactory
16%
11
Poor
1%
1
Answer Options
Very poor
0%
0
N/A
19
answered question
87
1% 0%
Very good
16%
Good
28%
Satisfactory
Poor
54%
Very poor
Note percentages are based on the 68 (78%) respondents that rated the service and excludes
those who don’t use the service.
Question 31 - How do you rate Landgate's Barcode Staff Calibration facilities and
services?
Response
Percent
19%
Response
Count
6
Good
53%
17
Satisfactory
25%
8
Poor
3%
1
Very poor
0%
0
Answer Options
Very good
N/A
56
answered question
88
3% 0%
Very good
Good
Satisfactory
Poor
Very poor
19%
25%
53%
Note percentages are based on the 32 (36%) respondents that rated the service and excludes
those who don’t use the service.
Question 32 - How do you rate Landgate's GNSS Test Range facilities and services?
Answer Options
Very good
Good
Response
Percent
Response
Count
18%
7
54%
0%
8%
21
Satisfactory
21%
8
Poor
8%
3
Very poor
0%
0
N/A
49
answered question
88
Very good
18%
21%
Good
Satisfactory
Poor
54%
Very poor
Note percentages are based on the 39 (44%) respondents that rated the service and excludes
those who don’t use the service.
Page 23 of 28
Question 33 - Is there a requirement for more regionally located EDM Calibration
facilities and services?
Response
Percent
Response
Count
Yes
30%
26
No
26%
23
N/A
44%
38
Answer Options
answered question
Yes
No
N/A
30%
26%
44%
87
Suggested locations

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Albany
Albany, and in future Katanning which is earmarked as a "Super-Town"
Albany
Albany
Bunbury
Esperance
But where except in our backyard in Geraldton!! At what cost to
establish? We looked at it some years back but realistically in this area
there wouldn't be 20 Total Stations to calibrate so I would question the
effective costs of that. It would be nice to have and would welcome further
discussion on practical options for that if others deem it pertinent.
North West suburbs
Port Hedland or Karratha
Karratha
Karratha/Port Hedland
Port Hedland
Karratha and Port Hedland
Port Hedland or Karratha
Pilbara
All major rural centres. Albany Bunbury, Geraldton & Kalgoorlie
A Facility already exists in Kalgoorlie
All calibrations are carried out at metro site
Question 34 - Do you have any other comments relating to Questions 30 to 33?
EDM Calibration:




We use the Busselton baseline for EDM calibrations
The only reason I have rated 31-33 poor is the location of the current
facilities, it adds a week to the calibration and servicing of our
instruments to get them from Port Hedland to Perth which can cause
logistics issues with our gear.
I don't mind using the Baseline in Perth but it is hard to program when
you travel to Perth only to find the Baseline occupied by local people that
can use it at any time without significant inconvenience. It basically
means a wasted trip, or additional accommodation, etc. I also recently
arrived to find the site obstructed by construction personnel that would
not move their equipment for us to use the baseline. It meant another trip
at a later date. Maybe a booking system for people that do have to travel a
significant distance (which I'm sure would bring its own problems!).
The Curtin Baseline does most of its measurements over distances
greater than the normal range. Therefore the accuracy of determining
prism constants are lost in the haze of distance.
Page 24 of 28
EDM Calibration software:



Baseline WA Calibration has problems with new versions of windows (I
currently use an old Windows Vista computer to process it as windows 7
does not work for me). An online version should be developed to avoid
this software install problem.
Q 30. A bit disappointed with EDM Calibration software not running on
Windows 7. We now have to have a PC dedicated to Windows XP so we
can run our Calibrations. 34. The ability to Calibrate in the Pilbara would
be very useful.
Provide information in the EDM calibration report on the status relative to
3rd party certification in a QA/QC environment
GNSS Testing:


Could RTK Observations be checked along the baseline as a test possibly
Q32 - is it possible for Landgate to identify a suitable set of SSMs in major
localities that could be used for GNSS test facilities. I appreciate that the
test facility in Perth is Pillar based but if Surveyors confirm their tribrachs
are set then a tripod based facility would be better than nothing. Why I
suggest Landgate nominates a set of SSMs is that they know which are
the more accurately fixed stations and part of a greater network.
Barcode Staff Calibration:

I have my doubts about the staff calibration facility. We find all Leica fibreglass staves are short. However the range predicts they are shorter than
we find in the field, when we compare the staff levelling with trig.
heighting. General comments:

A system that integrates the current calibration processes and full



additional QA processes for other instruments would be valuable. Using
CORS and Reg13 certificates would help in establishing regional sites to
undertake calibrations. Landgate should be educating the wider community as to the need for
them to understand that the geodetic survey network is for use by
suitable trained and experienced professionals who understand the
accuracy standards and how to achieve the best benefit for all the survey
marks placed throughout WA.
Don't really know what these question mean, you could educate people
like me more!
EDM calibration is important. I have not had the need for barcode staff
calibration, but high order engineering works may warrant the
requirement. GNSS technology is largely black box, the only use I could
see for a calibration is to check that the phase centre within units does
not shift. I don’t believe such GNSS calibrations are common practice
within the industry.
As a footnote to the EDM Calibration software issues on Windows 7, this has since been
resolved and all users have access to the latest Windows 7 compliant version.
Page 25 of 28
Section 5 – Datum 2020
The following background information was provided to participants in relation to the
implementation of a new Geodetic Datum:
GDA94 was implemented in WA in December 2000 after many years of planning.
This was a major change as we went from a datum based on the best fit for Australia
(AGD84) to a datum that aligned us with the coordinate system used by GPS and
resulted in a shift of around 190 metres. A new datum is now being planned for
initial delivery in 2015. This will be more like a refinement of GDA94 and will result
in a shift of around 1.8 metres. There are a number of reasons to make this change in
the datum. Primarily, CORS is facilitating an improvement in the accuracy that can
be achieved in the delivery of the datum – GDA94 has an uncertainty of 0.03 metres
at the fiducial marks whereas today CORS can deliver 0.001m. CORS has also
highlighted deficiencies in GDA94 that require users to perform local site
calibrations to manage the distortions of geodetic marks in some areas. Earth
dynamics is another contributing factor as these can now be modelled much better
and are also detectable by users – eg subsidence in the Perth basin, continental drift
etc. Positioning technology is continuing to evolve and our datum and spatial
datasets need to be accurate and consistent to maximize the value and use that this
technology will deliver. The new datum will not impact or change the AHD.
Question 35 - Do you believe this will have a serious impact on your business
processes? Your answer to this question will guide Landgate's approach to the
transition process.
Response
Percent
Response
Count
Yes
26%
23
Yes
No
53%
47
No
Don’t know
21%
18
Don't know
Answer Options
answered question
26%
53%
21%
88
Issues:








This depends on if the new datum is adopted by all stake holders straight
away and if transformation software and parameters are readily available.
The only problem we will have is uncertainty of which datum coordinates
are in, if not stated
Possible confusion with existing data on jobs and what grid they are on
This would be OK so long as the datum remained static - a dynamic datum
would be an unmitigated disaster for industry as current data systems
cannot handle time-variant coordinates
We're currently capturing data in GDA and I can see an issue with
converting all previous data sets to new data set
Mainroads has numerous datasets which will require conversion
Many Mining/Exploration companies will see this as an obstacle
especially if we are in an economic low period when the change occurs
Will be a significant period of transition where both datums will be used
Page 26 of 28




The time taken to convert old datasets, cost of software upgrades, time to
upgrade software, But the greatest impact will be on our clients who do
not understand the intricacies will struggle with their data management
and datum control when requesting and issuing data.
If Landgate provides transformation parameters between the two the
impact will be less.
Clients will request data in the new datum. Many historical surveys may
need transforming to be compatible with new data.
Is this a change of spheroid (GRS80)? Is this similar to the AGD66 to
AGD84 shift or is it more complicated than that. DMP has Graticular
tenements which shifted 200m with the introduction of GDA94. This
resulted in Gaps between pre and post GDA tenements. Will this proposed
change produce similar gaps of 1.8 metres
Issues due to small shift:






Managing data sets will be critical, because the relatively small shift will
be harder to detect.
We will have to be very careful as to the origin of any co-ordinates
adopted in the future as 1.8m is not as detectable in the field as 190m.
Will make the ability to see if data is GDA94 or the new datum quite
difficult if there is only a minimal shift
Similar with the shift from AGD84 to MGA94, however the subtle vector
shift could cause problems for some. Obviously surveyors will be allowed
to use either system at their discretion.
The 190m shift was large enough to know if the alternate datum was in
use. 1.8m won’t be as obvious.
As long as the support is there for transformations within GIS systems it
should not make a big difference, however the shift of 1.8m will be difficult
to detect compared to the AMG/ MGA shift of 200m
Change for good:









Yes, it will impact, particularly to the existing data. However, as with the
implementation of GDA, this will be a necessity that will benefit us all.
Painful but necessary, accept it and move forward!
We should be smart enough to evolve to the new system
Coordinates can be dynamic
My field of operation has been in greenfield environment where absolute
values are not critical
We shall need to invest in the ever improving technology in order to have
the capability to use the new datum and enjoy the improved accuracies
that will result. The government agencies and wider community must be
shown that the long-term benefits may mean increased costs in the short
term as organisations invest in the equipment and additional training
required.
I don't think this will have a serious impact on operations as I assume that
all datum information for GPS units will be provided from service agents
(ie C.R. Kennedy), who should be able to instruct survey firms of the
horizontal shift in coordinates
Great for new projects, but still need "Backward Compatibility"
Nowadays it is easier to keep records and therefore to retrieve old data for
a client etc. With a major shift it is "easier' to identify a changed datum but
the 1.8m may go undetected in some cases until much later. That is our
domain to deal with. I believe that this survey is about keeping up with
technology and geomatics in general. If there is a need to update due to
physical factors (subsidence and tectonics) then that has to happen to
maintain the overall realism of the data we provide. I believe we have
already seen some bad consequences of the geoid modelling upgrade to
the Ausgeoid - so no doubt there will be more if the hz changes too.
Page 27 of 28
Section 6 – Closing comments
Question 36 - Any other comments or feedback?









GDA94 does not need to change - tell GA to implement a dynamic datum
for scientific and their own use and to leave GDA94 alone - unless they
want to pay for all the software re-writes that will be required. GDA94 is
perfectly adequate for civil use, especially with all the computer power
available; the offset from ITRF can be more easily handled by
transformation.
We welcome the introduction of the CORS network, but it is well known
that a national system may have shortfalls in vertical accuracy.
Keep up the good work.
Things generally seem to be heading on the right track, although I get the
impression that a lack of funding for Landgate is having a serious impact
on the whole surveying structure in WA.
The state geodetic network has been appropriate to the technology up till
now. With increasing expectation for positional certainty, upgrading to
keep in touch with development in technology is essential
Some questions do not give enough range of answers. eg Q38 yes if I can
be of any help or use. no if I am required on a committee
As an "older generation" surveyor I've probably witnessed more of the
changes in the geodetic network than most current practising surveyors. I
think Landgate is responding well to the demands of industry.
Disrespect for ground marks is a growing problem for cadastral and
geodetic surveying marks. Many surveyors rely too much on things like
VRS and ignore the ground mark control of the previous surveys. This
results in local inaccuracy and erosion of good survey practice as
standards give way to the competition of price. Field audits need to be
more frequently carried out to ensure the diligence of all surveys is of an
equal standard.
Some of the current location descriptions are not relevant and need
upgrading
Question 37 - Would you like to participate in the industry review of the new draft
Geodetic Strategy?
Response
Percent
Response
Count
Yes
44%
39
Yes
No
56%
49
No
Answer Options
answered question
44%
56%
88
Names withheld.
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