The following is a brief description of the RADARSAT-1 satellite, managed by the Canadian Space Agency (CSA), with data processing and distribution performed by MDA's Geospatial Services (formerly RADARSAT International), also of Canada, or by Geoscience Australia.
The RADARSAT-1 satellite was launched on 4 November 1995 and has a Synthetic Aperture Radar (SAR) sensor on board. This sensor can operate in a variety of imaging modes to suit a range of applications. Additional information on the RADARSAT-1 satellite and data applications can be obtained from the MDA's Geospatial Services (formerly RADARSAT International).
The SAR sensor is an active microwave sensor capable of imaging the Earth regardless of time of day, cloud, haze or smoke over an area. The instrument is classified as 'active', as it emits the microwave energy necessary to image the Earth's surface. In contrast, 'passive' or 'optical' sensors rely on the Sun's reflected energy to image the Earth.
More general information on SAR is available through NASA's Jet Propulsion Laboratory: What is Imaging Radar?
The SAR sensor on RADARSAT-1 has the unique capability to acquire data in any one of a possible 25 imaging modes. Each mode varies with respect to swath width, resolution, incidence angle and number of looks. Because different applications require different imaging modes, RADARSAT-1 gives users tremendous flexibility in choosing the type of SAR data most suitable for their application.
A summary of the imaging modes and their parameters is shown below. The following diagram shows most of the image modes available.
| Beam Mode |
Beam Position |
Incidence Angle (°) |
Nominal Resolution (metres) |
Nominal no. of Looks |
Nominal Area (km) |
|---|---|---|---|---|---|
| Fine |
F1 # |
37 - 40 |
10 |
1 x 1 |
50 x 50 |
| Standard |
S1 |
20 - 27 |
30 |
1 x 4 |
100 x 100 |
| Wide |
W1 |
20 - 31 |
30 |
1 x 4 |
165 x 165 150 x 150 |
| ScanSAR Narrow |
SN1 |
20 - 40 |
50 |
2 x 2 |
300 x 300 |
| ScanSAR Wide |
SW1 |
20 - 50 |
100 |
2 x 4 |
500 x 500 |
| Extended High |
H1* |
49 - 52 |
25 |
1 x 4 |
75 x 75 |
| Extended Low |
L1 |
10 - 23 |
35 |
1 x 4 |
170 x 170 |
* This option is currently unavailable from the RADARSAT-1 satellite. |
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# Ten additional Fine Beam Mode positions are now available by moving each position closer or further from nadir. |
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| Frequency |
5.3 GHz |
|
|---|---|---|
| RF Band Width |
11.6, 17.3 or 30.0 MHz |
|
| Band Name |
C Band |
|
| Wavelength |
56 mm |
|
| Incidence Angle |
10 - 59 degrees |
|
| Ground Resolution |
10 - 100 metres |
|
| Swath Width |
50 - 500 km |
|
| Polarisation |
HH* |
|
* H=horizontal. |
||
| General Application |
Advantage |
|---|---|
| Tropical / coastal studies |
Radar penetrates cloud, fog and rain |
| Coastal / lakes studies |
HH polarisation best for land/water discrimination |
| Discerning man-made features |
These features strongly reflect radar energy |
| Assessment of soil and vegetation moisture content |
Amount of SAR backscatter is related to this |
| Disaster studies (Volcanic eruptions, dust storms or flooding) |
Radar penetrates dust and cloud |
| Remote area studies |
Global coverage |
| Geology |
Structural studies; exploration |
| Land use (including agriculture and forestry) |
Mapping and change assessment |
For enquiries about satellite programming and help choosing the best product for specific applications, contact: Earth Observation Client Services. Clients can also contact other Australian organisations who provide RADARSAT consultancy services, and are distributors of other Geoscience Australia Remote Sensing products.