MEASURING SEA ICE
GeoSAR was developed as joint effort between NASA’s Jet Propulsion Laboratory and Fugro
GeoSAR:
from jungle canopy to Arctic ice
Over the past three years, Fugro has teamed up with university and industry
partners to develop a specialised ice management capability that enables mapping,
characterisation and monitoring of ice structures over large geographical areas.
Here, Fugro's Arctic Team discuss their award-winning technology
A New Discovery
In 2012, Fugro began investigating
the potential use of its GeoSAR system
to provide ice thickness data over large
project areas. GeoSAR is an airborne
dual-band, dual-sided radar mapping
technology, developed as a joint
16 AUTUMN 2014 www.frontierenergy.info
effort between NASA’s Jet Propulsion
Laboratory and Fugro. It has been used
extensively to map rugged terrain and
dense tree canopy in equatorial regions. In
such locations, its unique configuration of
interferometric radar collects information
about surface features (X-band) and
penetrates thick foliage for near bare
earth (P-band). Flown on a GulfstreamII jet aircraft, GeoSAR maps swaths
simultaneously on both sides of the
aircraft to generate high quality digital
elevation models and imagery.
In 2010, the GeoSAR team left the
Eventually the team expects
to be able to identify weak
points in the ice, which will
help vessel captains break ice
safely and efficiently
southern hemisphere and flew north to
tackle an altogether different geography.
Alaska had just embarked on a statewide
digital mapping initiative to update its
decades-old topographic datasets. As
part of that effort, Fugro was tasked with
collecting data over the Alaska Range,
an area comprising extreme elevation,
year-round snowpack, and glacial terrain.
It was during this project that Fugro
discovered the ability of GeoSAR’s
P-band sensor to penetrate snow and ice.
Realizing the potential application of this
technology to offshore ice management,
Fugro’s research and development team
began working toward the design of a
large-area ice thickness mapping solution.
Testing the Theory
The general theory behind GeoSAR ice
thickness mapping is that if the X-band
signal provides elevation data for the
top of the ice surface and the P-band
signal penetrates to the bottom of the
ice surface, then the difference of these
two figures is the depth, or thickness, of
the ice. This theory was first tested in
April 2012, along areas of the Alaskan
Beaufort and Chukchi Seas. Working with
university and private industry partners,
the team acquired X- and P-band
GeoSAR data, as well as multiple ground
control sources, including airborne- and
ground-based electromagnetic data, ice
cores, ice depth holes, and laboratory
work to determine the chemical makeup
of the ice cores. Although only first-year
ice was involved in the initial research
programme: results were positive,
indicating significant ice penetration and
demonstrating the potential to distinguish
additional ice characteristics, such as
deformation and age.
In April 2013, Fugro performed a
follow-up adding a second industry
partner to the research effort. Data
collection again spanned across areas of
the Alaskan Beaufort and Chukchi Seas,
including a potential drilling location.
Gains in project planning, mobilization,
and processing helped streamline the
overall process, but once again a lack of
multiyear ice in the project area kept the
Photos: Fugro
I
ce management remains one of the
more challenging aspects of Arctic
exploration and development.
With millions of kilometres of the Arctic
Ocean covered in constantly moving ice,
operators need accurate, current and
detailed information about ice conditions.
For years, satellite imagery has been the
standard tool used to understand regional
ice conditions. These datasets, which can
be acquired by optical- or radar-based
sensors, provide a good two-dimensional
overview of ice location and extent.
What satellite data lacks, however, is
the ability to determine ice thickness, a
characteristic critical to engineering Arctic
infrastructure and to reducing risk in
everyday Arctic operations.
Traditional methods for obtaining ice
thickness measurements include drilling
holes in the ice, dragging electromagnetic
radar sensors on sleds across the ice
surface, or deploying autonomous
underwater vehicles (AUVs) equipped
with upward-looking sonar systems
to map the ice from the bottom up.
Each of these techniques is effective
for small-to-medium sized studies, but
their application is not efficient for the
massive scale required by seasonal ice
management programmes.
MEASURING SEA ICE
over an area known to contain
in-situ multiyear and first-year ice.
Unlike the projects that came before,
the sea ice was stationary, containing
a good mix of multiyear ice and
first-year ice. While data analysis is
still underway, preliminary results
are promising.
“We are seeing definite P-band
penetration into multiyear sea ice,”
said Joe Jones, Fugro’s GeoSAR
programme manager. “We are
still determining the depth of that
penetration, but so far the results are
The P-band signal penetrates to the bottom of the ice surface
just what we expected.” In addition,
the system has demonstrated the
team from testing P-band penetration
ability to successfully classify sea ice into
over these most dangerous types of ice
three categories: multiyear, first-year, and
structures. Determined toward a common deformed ice. It can also identify ice islands
goal, Fugro and its partners convened
(glacial ice) embedded within sea ice.
during the fall to design a program for the
“These are significant findings,” Jones
following year, this time selecting more
precise project locations and adding an
additional university partner to the mix.
Third Time Is the Charm
This March and April, the team
initiated a third sea ice mapping
programme, this time focused
approximately 100 miles northwest of
Resolute Bay in the Canadian Beaufort
In 2013 a lack of multiyear
ice in the project area kept
the team from testing P-band
penetration over these most
dangerous types of ice structures
said. “The ice thickness data and ice
class information will be fused into a
single product, allowing our clients to
complete information for effective ice
management.” Building on this most
recent project success, Fugro and its
partners plan a fourth data collection
programme in 2015 during the summer,
when ice management is most needed.
A Complete Solution
As part of the research and development
effort, Fugro has developed an in-field
processing system that enables X-band and
P-band data processing immediately after
each flight. All products can be created and
delivered to the client within 4 hours of
landing the aircraft. Deliverables include
a multi-layered GIS database identifying
dangerous chunks of ice and ice types.
Eventually, the team expects to be able to
identify weak points in the ice, which
will help vessel captains break ice safely
and efficiently. Fugro is also exploring
how to combine the ice thickness
capability with existing oceanographic
and ice monitoring capabilities to provide
a complete solution for oil and gas
exploration and development activities,
including potential oil spill preparedness
and response applications.
53
YEARS
EXPLORING
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