| SAR Operating Modes
| Standard Beam Details
| Alternate Beam Angles
| Tape Recorder Details
| Downlink Details

RADARSAT SAR Operating Modes

SAR Mode | Nominal Swath Width (km) | Nominal Swath Range from Nadir Offset (km) | Nominal Range Resolution (IRW) (m) | Azimuth Resolution (IRW) (m) | Incidence Angle Range (deg)
--- | --- | --- | --- | --- | ---
Standard Beams: 7 beams, >10% overlap, ~250 km nadir offset | 100 | 0-100 60-160 140-240 210-310 280-380
340-440
400-500
26
22
27
25
24
22
21
28
20
49
Wide Swath Beams: 3 beams, 3% overlap, ~250 km nadir offset | 150 | W1 0-150 W2 145-295 W3* 290-420 | 35 27 23 | 28 | 20 45
Fine Resolution: 5 beams, 10% overlap, ~500 km nadir offset | 50 | F1 0-50 F2 45-95 F3 90-140 F4 135-185 F5 170-220 | 9 9 9 8 8 | 9 | 35 49
Narrow SCANSAR: ~250 km nadir offset ~400 km nadir offset | 300 | Uses Beams: W1,W2 W2, 5, 6 | 50 | 50 | 20-50 32-46
Wide SCANSAR: ~250 km nadir offset ~250 km nadir offset | 500 440 | Uses Beams: W1,W2,W3, 7 W1, W2, 5, 6 | 100 | 100 | 20-50 20-46
High Incidence Beam: 6 beams, 3% overlap, ~500 km nadir offset | 75 | EH1 EH2 EH3 EH4 EH5
EH6
25
28
50
60
Low Incidence Beam: ~125 km nadir offset | 75 | EL1 | 25 | 28 | 10-20
* W3 is not recommended because this beam is intended for use in SCANSAR and the single beam product contains nadir ambiguity.

This table is courtesy of the Canadian Space Agency

|  | Standard Beam Details Look angles and Incidence angles of the seven Standard Beams, specified for near and far ranges.

Standard Beam Angles
Beam No. | Look Angles (°) | Incidence Angles (°)
--- | --- | ---
| Near | Far | Near | Far
1 | 17.3 | 23.8 | 20.0 | 27.4
2 | 21.3 | 27.4 | 24.2 | 31.2
3 | 26.7 | 32.2 | 30.4 | 36.9
4 | 29.4 | 34.5 | 33.6 | 39.6
5 | 31.9 | 36.6 | 36.5 | 42.2
6 | 36.0 | 40.1 | 41.4 | 46.5
7 | 38.7 | 42.3 | 44.9 | 49.4
Reference: "The Radarsat Synthetic Aperture Radar Development", Luscombe, A.P. et al; in: Canadian Journal of Remote Sensing, Volume 19, No. 4, Nov-Dec 1993, p 301

|  | Standard Beam Performance Parameters Estimates for performance parameters of the Standard Beam, representing worst-case specifications.

Standard Beam Performance Parameters
Swath Width | > 100km
Range Resolution | < 25m
Azimuth Resolution (four looks) | < 28m
Peak Impulse Response Sidelobe | < -20dB
Signal Dependent Noise Ratio | < -10dB
Range Ambiguity Ratio | < -20dB
Azimuth Ambiguity Ratio | < -20dB
Noise-Equivalent Sigma Nought | < -20dB
Equivalent No. of Independent Looks | > 3.4
Global Dynamic Range | > 30dB
Radiometic Accuracy (goals) | 1.0dB (in 100km by 100km scenes) 1.5dB (within one orbit) 2.0dB (over three days) 3.0dB (over mission life)
Image Locatin Accuracy | < 1.5km
Geometric Distortion (within 100km by 100km scene) | < 40m
Reference: "The Radarsat Synthetic Aperture Radar Development", Luscombe, A.P. et al; in: Canadian Journal of Remote Sensing, Volume 19, No. 4, Nov-Dec 1993, p 300

|  | Angles for Alternate Beams Look and incidence angles for the edges of the swaths of the alternative beams (i.e. not the Standard Beams)

Beam No. | Look Angles (°) | Incidence Angles (°)
--- | --- | ---
Near | Far | Near | Far
Wide Swath Beams
W1 | 17.7 | 27.4 | 20.0 | 31.2
W2 | 27.0 | 34.4 | 30.8 | 39.5
Fine Resolution Beams
F1 | 32.2 | 34.9 | 36.9 | 40.1
F2 | 34.2 | 36.7 | 39.3 | 42.3
F3 | 36.1 | 38.2 | 41.6 | 44.2
F4 | 37.7 | 39.7 | 43.6 | 46.0
F5 | 39.1 | 41.1 | 45.3 | 47.8
SCANSAR
2-beam | 17.3 | 34.4 | 20.0 | 39.5
4-beam | 17.3 | 42.3 | 20.0 | 49.4
Reference: "The Radarsat Synthetic Aperture Radar Development", Luscombe, A.P. et al; in: Canadian Journal of Remote Sensing, Volume 19, No. 4, Nov-Dec 1993, p 302

|  | Tape Recorder Details The Sar data are normally received while the satellite is within view of one of the Data Reception Facilities on the ground. However, these stations are not sufficient in number to provide the global coverage needed to meet the mission data acquisition objectives.

- Two tape recorders (one of which is normally redundant) are provided to record raw SAR data on-board the satellite and to replay these data later for transmission toa DRF.
- Each tape recorder is capable of continuously recording raw SAR data for a period not less than 10 minutes.
- Each tape recorder is capable of continuously recording and playing back raw SAR data at a rate of not less than 85 Mb/s.
- It will be possible to operate each recorder independantly but both recorders cannot be powered simultaneously.
- Recorded SAR data, upon palyback, will be capable of providing the same image quality as the original data within the recorded swath width.
- The tape recorder subsytem will have a high probability (i.e., > 0.95) of being able to record and replay at least 3000 hours of data, assumed to be stored at an average rate of 10 minutes per orbit in three separate segments and replayed in three separate segments.

|  | Downlink Details The raw SAR data wil be transmitted from the satellite to a Data Reception Facility (DRF) over X-band radio frequency links.

- All auxiliary data that is available in the satellite and is neccessary for data processing and image quality monitoring and calibration will be included in the downlinked data stream.
- An X-band RF link centred at 8105 MHz will be used for the transmission of real-time data at a rate of 105 Mb/s.
- Another X-band link centred at 8230 MHz will be used for the transmission of tape recorded data at a rate of 85 Mb/s.
- It will be possible to transmit real-time data and recorded data simultaneously by using both links.

RADARSAT Overview
RADARSAT Technical Specifications - Summary