Title: Welcome to MDA
1RADARSAT-2 Radargrammetry
MDA Proprietary
Marco van der Kooij Director, GSI Services MDA
Geospatial Services mvanderkooij_at_mdacorporation.co
m 613-727-1087
Alaska DEM Workshop July 22-23, 2008 Anchorage,
Alaska
2Contents
- Introduction, GSI Services, Radarsat-2
- ERS InSAR example, N-Canada
- Radarsat-2 Radargrammetry validation experiment
- Strengths of Satellite radar solution
3MDA Geospatial Services
- Data Business
- Service Business (after acquisition of Vexcel
Canada in 2007) - InSAR deformation Services (Oil and Gas, Mining)
- Digital Elevation Models
- Land based services
- Maritime services
4RADARSAT-2Testing and Launch
- Satellite completed July 24 2007
- Shipped to the launch site (Baikonur, Kazakhstan)
November 12, 2007 - Successful launch and deployment December 14,
2007 - Commissioning phase completed April 15, 2008
5RADARSAT-2 Mission Overview
- Co-funded by Canadian Space Agency (CSA) and
MacDonald Dettwiler (MDA) - Data continuity from RADARSAT-1
- all RADARSAT-1 imaging modes supported
- plus many additional capabilities
- Mission duration 7 years
- Designed, built, operated and owned by MDA
6RADARSAT-2 Beam modes and features
- High resolution
- 3 m
- multi-look 10 m
- SpotLight
- Polarimetric modes
- single/dual polarization
- quad-pol
- Right and left-looking capability
- Enhanced ground system providing
- efficient satellite tasking
- (12 - 24 hours routine)
- faster data processing
- Calibrated data
7RADARSAT-2 Imaging Modes
8Vancouver, Ultra-fine
9Detail, Vancouver Airport, Ultra-Fine
10Polarization Concepts
- For imaging radar applications, the polarization
state of the radar wave is defined
with-respect-to the Earths surface - Co-polarized
- transmit/receive horizontal (HH)
- transmit/receive vertical (VV)
- Cross-polarized
- transmit horizontal, receive vertical (HV)
- transmit vertical, receive horizontal (VH)
11Fine Quad PolarimetryDevon Island
12MDA GSIDEMs
- InSAR
- Atlantis Scientific / Vexcel InSAR software for
elevation mapping - MDA InSAR toolkit for elevation mapping
- Northern Canada, Baffin Island, 150,000 scale
mapping, 7 m vertical accuracy for low to
moderate terrain - Radargrammetry
- Commercial off-the-shelf
- Vexcel Radargrammetry
- Finishing, based on SRTM methodology but further
automated - Photogrammetric base mapping editing tools and
expertise
13ERS Tandem InSAR DEMs Baffin Island7 m LE90
for low to moderate topography
- Y. Robitaille (PM, CTI) The best 150,000
scale DEMs we have ever seen. Vertical accuracy
is 7 m LE90 - Elevation data available to the public through
Can. Gov. portal
14Radar across Track Geometry
Layover
Shadow
Projection of Radar Image
Shadow behind peaks
Mountains overlay lake
Lake
15Radar Triangulation (2-D)
Baseline
Height
Across Track
2-D Coordinate System
2-D coordinates determined by intersecting arcs
16Across Track Geometry - Single Stereo Pair
100 km
800 km
50 km
17RADARSAT-2 Mapping Flexibility This pattern is
repeated every 24 days
MF
MF
MF
Repeat paths of the satellite...
S7
S7
Three stereo models
18Radargrammetry with Radarsat-2(compared with
Radarsat-1)
- Higher resolution, more looks better matching,
more features - Multi-look fine (9 x 9 m, 4 looks)
- Ultra-fine (2 m x 3 m, 1 look)
- Spotlight (2 m x 1 m, 1 look)
- More favourable stereo geometry for high
resolution modes (full flexibility of incidence
angles (30-50 deg) - Repeat pattern (24 days) is suitable for stereo
angles - The combination of left and right looking modes
improve the acquisition capacity and geometry
(potential of 4 azimuth look directions
(ascending/descending and left/right) - Orbit accuracy improved (GPS). Reduced need for
ground control points. - Large acquisition capacity for commercial
acquisitions (87.5 of capacity, 2360 scenes per
day)
19Area of Interest
- Roughly centered on Morrison, Colorado
- Also the test site of other Digital Elevation
Models (DEM) evaluations - Benefit of multiple control and evaluation
datasets
Denver
MDA Proprietary
Alaska DEM Workshop June 22-23 Anchorage -
Alaska
20Validation activity Radarsat-2 Radargrammetry
- R-2 DEM from 1 pair of UF
- Acquired April 1 11, 2008
- R-2 DEM from 1 pair of MLF
- Acquired March 1 11, 2008
- 42 National Geodetic Survey (NGS) benchmark GPS
points collected (sub-meter accuracy) for QA - USGS NED 10 m DEM
- SRTM 1 arc second and 3 arc second datasets
MDA Proprietary
Alaska DEM Workshop June 22-23 Anchorage -
Alaska
21Accuracy Evaluation Specifics
- 43 NGS points were collected and 42 used
- 1 NGS point was removed due to obvious erroneous
value - 28 remaining points in terrain less than 20
degrees - 14 remaining points in terrain more than 20
degrees - (highlighted in green)
MDA Proprietary
Alaska DEM Workshop June 22-23 Anchorage -
Alaska
22NGS Benchmark Data
- Reference data set for absolute vertical accuracy
tests
MDA Proprietary
Alaska DEM Workshop June 22-23 Anchorage -
Alaska
23Theoretical accuracy (LE90)based on Radarsat-1
measurements
Radarsat-1
Radarsat-2 Multi-Look-Fine
Radarsat-2 Ultra-Fine
Radarsat-2 Spotlight
24Theoretical accuracy (LE90)Compared with
Radarsat-2 measurements
Radarsat-1
Radarsat-2 Multi-Look-Fine
Radarsat-2 Ultra-Fine
Radarsat-2 Spotlight
25SRTM 90m
SRTM 30m
NED 10m
Ultrafine 30m
Multi-Look 30m
MDA Proprietary
Alaska DEM Workshop June 22-23 Anchorage -
Alaska
26Statistical summaryAbsolute accuracy (LE90)
LE90, abs (m) NED SRTM 30 SRTM 90 UF MF
     Â
lt 20 deg 7.03 6.3 18.7 13.0 9.7
gt 20 deg 11.1 15.7 30.5 20.5 18.2
All 8.2 14.0 22.0 19.3 16.1
MDA Proprietary
Alaska DEM Workshop June 22-23 Anchorage -
Alaska
27Statistical SummaryStandard Deviation of
Subtraction Images
NED SRTM 30 SRTM 90 UF MF
     Â
NED 7.75 11.16 7.07 7.61
SRTM 30 8.29 6.08 9.06
SRTM 90 9.34 11.42
MDA Proprietary
Alaska DEM Workshop June 22-23 Anchorage -
Alaska
28Improved accuracy
- Additional stereo pairs (ascending AND
descending) to cover acquisition holes and for
error reduction - Automatic finishing methodology to filter
outliers and apply water body flattening,
drainage network consistency - Photogrammetric editing techniques
- Use of higher resolution beam modes (Ultra-fine
and Spotlight mode)
29Horizontal and vertical control
- Accurate orbit data (several m) allow absolute
horizontal control of DEM - Local sources of vertical control (e.g. NGS,
Aster) - Validation and local collaboration
30Acquisition approach for successful coverage of
slopes
- Prior modeling of layover, foreshortening,
shadow. - 1 ascending pair and 1 descending pair for each
location Improved vertical accuracy - Nearly constant, suitable incidence angle range
(38-50 degrees) to optimize successful coverage
of slopes - For steeper terrain
- Additional smaller incidence angle pairs to
maximize slope coverage - Additional azimuth coverage from right looking
modes if necessary - Use of Spotlight mode for key targets (e.g. Mt.
McKinley)
31Building of archive
- Currently no archive exists
- Archive can be built up quickly with Multi-look
Fine, complemented with Ultra-fine and Spotlight - Independent of cloud cover!
- Acquisition during winter and summer
- Large acquisition capacity
32Deliverables
- DSM (Digital Surface Model), spacing 10-30 m
- Ortho SAR images
- Breaklines
- Features
- Water bodies, rivers etc.
- Licensing
- DEMs negotiable
- Price lt 10 M
33Summary
- Radarsat-2 is a viable source of DEMs
- Radarsat-2 is reliable and with a very large
capacity for mapping - Potential collaboration for downlink and
applications expertise at Alaska SAR facility - Medium to high resolution source imagery
(including Spotlight) - MDA has experience in providing elevation data
for Northern Canada for operational mapping - Radarsat-2 could play a role in monitoring
environment and for special applications (e.g.
deformation monitoring)