RADARSAT-2

Long name RADARSAT-2
Short name RS2
Sensor type Synthetic-aperture radar (SAR)
Platform RADARSAT-2
Frequency 5.405 GHz
Band (wavelength) C (5.5 cm)
Polarization HH, HV, VH, VV (fully polarimetric)
Key file name (use to open data set) product.xml or RS2_*.ntf
Supported file extensions N/A
Data distributor MacDonald, Dettwiler and Associates (MDA)
Sections

Data product name and description
Distribution disk files
Returned data for supported format
References

Data product name and description

During image acquisition, RADARSAT-2 can operate in one of three sensor modes:
  • Single beam: A stripmap SAR mode in which operation, beam elevation, and profile remain constant.
  • ScanSAR: Uses a combination of two or more single beams covering adjoining swaths. The beams are operated sequentially, each with a series of pulse transmissions and receptions, so that data is collected from a swath wider than possible with a single beam, which repeats in cycles.
  • Spotlight: The beam steers electronically to focus on the area of interest for a longer aperture time, which produces products of finer azimuth resolution.

The acquisition modes of the RADARSAT-2 sensor are as described in the following tables.

Note: The information provided herein is based on the RADARSAT-2 reference documentation cited under References.
Mode Swath width (km) Resolution (range x azimuth, m)* Polarization Description/notes
Spotlight [SLA] 18 1.6 x 0.8 Single (HH or HV or VH or VV) The Spotlight imaging mode focuses 19 beams at various angles of incidence, ranging from [SLA70] (19.9° to 21.5°) to [SLA9] (36.4° to 37.6°).
Ultra-Fine [U] 20 1.6 x 2.8 Single (HH or HV or VH or VV) The Stripmap submode Ultra-Fine is intended for applications that require very high spatial resolution. Ultra-Fine focuses 27 beams at various angles of incidence, ranging from [U70] (19.9° to 21.5°) to [U17] (42.2° to 43.3°).
Multi-Look Fine [MF] 50 3.1 x 4.6 Single (HH or HV or VH or VV) The Stripmap submode Multi-Look Fine covers the same swaths as the Fine [F] submode. Products with multiple looks in range and azimuth are generated approximately at the same spatial resolution as Fine products, but with multiple looks and, therefore, improved radiometric resolution.

Multi-Look Fine focuses 26 beams at various angles of incidence ranging from [MF23] (30.0° to 33.4°) to [MF6F] (47.5° to 49.9°).

Fine [F] 50 5.2 x 7.7

Single (HH or HV or VH or VV)
Dual (HH+HV or VV+VH)

The Stripmap submode Fine is intended for applications that require finer spatial resolution than the Standard [S] submode.

Fine focuses 26 beams at various angles of incidence ranging from [FQ1] (18.4° to 20.4°) to [FQ31] (48.3° to 49.4°).

Fine Quad-Pol [FQ] 25 5.2 x 7.6 Quad (HH + HV + VV + VH) Fine Quad provides full polarimetric imaging with the same spatial resolution as the Fine submode, but at the expense of the swath width.

Fine Quad focuses 31 beams at various angles of incidence ranging from [FQ1] (18.4° to 20.4°) to [FQ31] (48.3° to 49.4°).

Standard [S] 100

9.0 x 7.7
—or—
13.5 x 7.7

Single (HH or HV or VH or VV)
Dual (HH + HV or VV + VH)

The Stripmap submode Standard provides a balance between fine resolution and wide coverage, and between spatial and radiometric resolutions.

Standard focuses eight beams at various angles of incidence ranging from [S1] (20.0° to 27.2°) to [S8] (48.5° to 52.1°).

Standard Quad-Pol [SQ] 25

9.0 x 7.6
—or—
13.5 x 7.6

Quad (HH + HV + VV + VH) The Stripmap submode Standard Quad-Pol provides full polarimetric imaging with the same spatial resolution as Standard, but at the expense of the swath width.

Standard Quad-Pol focuses 31 beams at various angles of incidence ranging from [SQ1] (18.4° to 20.4°) to [SQ31] (48.3° to 49.4°).

Wide [W] 150 13.5 x 7.7

Single (HH or HV or VH or VV)
Dual (HH + HV or VV + VH)

The Stripmap submode Standard Quad-Pol provides imaging of wider swaths than Standard, but at the expense of slightly coarser spatial resolution in some cases.

Wide focuses three beams at various angles of incidence ranging from [W1] (20.0° to 31.9°) to [W3] (38.7° to 45.3°).

Extended High [EH] 75 13.5 x 7.7 Single (HH) The Stripmap submode Extended High focuses six beams at various angles of incidence ranging from [EH1] (48.5° to 52.1°) to [EH6] (56.8° to 59.3°).

Because the beams operate outside the optimum scan-angle range of the SAR antenna, some degradation of image quality can be expected in comparison with Standard.

Extended Low [EL] 170 9.0 x 7.7 Single (HH) The Stripmap submode Extended Low is a single low-incidence beam [EL1] (10.0° to 23.1°).

Because the beam operates outside the optimum scan-angle range of the SAR antenna, some degradation of image quality can be expected in comparison with Standard.

ScanSAR Narrow [SCN] 300 81 to 38 x 40 to 70

Single (HH or HV or VH or VV)
Dual (HH + HV or VV + VH)

ScanSAR Narrow provides coverage of a ground swath approximately double the width of Wide [W]. There can be two swath positions using various combinations of physical beams:
  • SCNA (20° to 39°), which uses physical beams W1 and W2
  • SCNB (31° to 47°), which uses physical beams W2, S5, and S6
ScanSAR Wide [SCW] 500 163 to 73 x 78 to 106

Single (HH or HV or VH or VV)
Dual (HH + HV or VV + VH)

ScanSAR Narrow provides coverage of a ground swath approximately triple the width of Wide [W]. There can be two swath positions using various combinations of physical beams:
  • SCWA (20° to 49°), which uses physical beams W1, W2, W3, and S7
  • SCWB (20° to 46°), which uses physical beams W1, W2, S5 and S6
Ocean Surveillance [OSVN] 500 118 to 53 x 53 to 104 (SCF)

Single (HH or HV or VH or VV)
Dual (HH + HV or VV + VH)

Ocean Surveillance ScanSAR Beam Mode provides images of very wide swaths similar to ScanSAR Wide, but with finer resolution and improved ship-detection performance similar to ScanSAR Narrow.
Ship Detection [DVWF] 450 103 to 71 x 40 to 81 (SCF) Single (HH or HV or VH or VV) Ship Detection ScanSAR Beam Mode provides images of very wide swaths similar to ScanSAR Wide, but is designed primarily for ship-detection purposes. The mode uses the highest data-compression ratios, so it has the highest signal-dependent noise levels, and is designed to sacrifice visual appeal to provide the most effective detection of small ships over very wide areas.

* Resolution is always single-look complex (SLC) unless noted otherwise.

Note: After its launch in 2007, several additional acquisition modes have been added to the RADARSAT-2 sensor, and each is a variant of its corresponding original acquisition mode: Wide Ultra-Fine, Extra-Fine, Wide Multi-Look Fine, Wide Fine, Wide Fine Quad-Pol, Wide Standard Quad-Pol, Ship Detection, Ocean Surveillance.

Each acquisition mode is described in the following table.

Processing level Acquisition mode Description/notes
Single-look complex (SLC)

[SLA]
[U], [MF], [F], [S], [W], [EH], [EL], [FQ], [SQ]

Complex data. Slant-range geometry. Georeferenced.

Each image pixel is represented by a complex (real I and imaginary Q) magnitude value. No interpolation into ground-range coordinates is performed during processing for SLC image products; therefore, the range coordinate is given in radar slant range rather than ground range.

SAR georeferenced extra (SGX)

[SLA]
[U], [MF], [F], [S], [W], [EH], [EL], [FQ], [SQ]

Detected (magnitude) data. Ground-range geometry. Georeferenced (path image plus).

SGX products have very fine pixel spacing that is chosen to meet the Nyquist criterion in all areas of the image, which ensures that all of the image information is preserved and makes the imagery suitable for post-processing.

SAR georeferenced fine (SGF)

[SLA]
[U], [MF], [F], [S], [W], [EH], [EL], [FQ], [SQ]

Detected (magnitude) data. Ground-range geometry. Georeferenced (path image).

SGF images are the same as SGX except in pixel spacing. SGF images are generated with standard ground-coordinate pixel dimensions, which are generally larger than those of the corresponding SGX images. SGF images are therefore appropriate for applications in which the reduction in product volume is important, and where full precision is not needed.

ScanSAR narrow beam (SCN) [SCN] Detected (magnitude) data. Ground-range geometry. Georeferenced (path image).

SCN is a conceptual ground-range coordinate, multi-look image that (for historical reasons) is used to refer to SGF images produced from data obtained in the ScanSAR narrow-beam mode, by using either two or three physical beams.

ScanSAR wide beam (SCW) [SCW] Detected (magnitude) data. Ground-range geometry. Georeferenced (path image).

SCW is a ground-range coordinate, multi-look image that (for historical reasons) is used to refer to SGF products produced from data obtained in ScanSAR Wide Beam Mode using four physical beams.

ScanSAR fine (SCF)

ScanSAR sampled (SCS)

[SCN] [SCW] [OSVN] [DVWF] Detected (magnitude) data. Ground-range geometry. Georeferenced (path image).

With the standard ScanSAR beam modes (ScanSAR narrow and ScanSAR wide), SCF and SCS are similar to SCN or SCW (as applicable to the beam mode), except that each supports additional processing options and metadata fields (SCN and SCW products provide backwards compatibility with existing processes and applications).

SAR systematic geocorrected (SSG)

[SLA]
[U], [MF], [F], [S], [W], [EH], [EL], [FQ], [SQ]

Detected (magnitude) data. Systematic geocoded (map image).

An SSG product is generated by geocorrection of a single-beam or spotlight product. The geocorrection process for SSG products does not include the use of ground control points (GCP). Geocorrection can include either orthorectification using a DEM or can be based on a fixed elevation above a reference ellipsoid, which you can specify.

SAR precision geocorrected (SPG)

[SLA]
[U], [MF], [F], [S], [W], [EH], [EL], [FQ], [SQ]

Detected (magnitude) data. Precision geocoded (precision map image).

SPG is similar to SSG, except that SPG is geocorrected by using precise GCPs.

Distribution disk files

Radarsat-2 data is distributed in two formats:
Table 1. Radarsat-2 single-file structure
File name Format Required Contents/details
RS2_*.ntf NITF 2.1 Yes Key file name.

Contains all imagery and metadata that applies to the data set.

Table 2. Radarsat-2 multiple-file structure
File name Format Required Contents/details
product.xml Extensible Markup Language Yes Key file name.

Contains metadata that applies to the data set.

imagery_n.tif GeoTIFF Yes Image data, one file for each polarization channel, where n represents HH or HV or VH or VV, as applicable.
BrowseImage.tif TIFF No Image browse file in TIFF format.
lutSigma.xml Extensible Markup Language Yes, for all products except SSG and SPG LUT to transform raster values to sigma-nought (sigma0) values.
lutBeta.xml Extensible Markup Language Yes, for all products except SSG and SPG LUT to transform raster values to beta-nought (sigma0) values.
lutGamma.xml Extensible Markup Language Yes, for all products except SSG and SPG LUT to transform raster values to gamma-nought (sigma0) values.
RS2_EULA_*.pdf Portable Document Format No Product end-user license agreement (EULA).
Readme.txt ASCII No Readme file.
label.txt ASCII No Label file.

Returned data for supported format

RADARSAT-2 data can be opened directly in its raw vendor format or imported into a PCIDSK (*.pix) file by using the key file. For optimal processing, use the PCIDSK format.

In the following table, the data structure after it is imported into a PCIDSK file is described.

Warning: Data sets for this sensor are organized in a specific folder structure on disk. GDB uses this structure and the file names to identify the data product type. Do not alter the folder structure or any file names prior to data ingestion to ensure the image data and auxiliary information are imported correctly.
Data product Data returned Details

Single-look complex (SLC)
Single polarization
[U], [MF], [F], [S], [W], [EH], [EL]

1 x [C16S] raster channel (uncalibrated)
—or—
1 x [C32R] raster channel (calibrated)

1 x [GCP] ground control points
1 x [TEX] main product annotation
1 x [ORB] orbit segment
1 x [BIN] rational function model segment
1 x [ARR] incidence angle array

Data can be calibrated in sigma, beta, or gamma nought.

Single-look complex (SLC)
Dual polarization
[F], [S], [W]

2 x [C16S] raster channels (uncalibrated)
—or—
2 x [C32R] raster channels (calibrated)

1 x [GCP] ground control points
1 x [TEX] main product annotation
1 x [ORB] orbit segment
1 x [BIN] rational function model segment
1 x [ARR] incidence angle array

Data can be calibrated in sigma, beta, or gamma nought.

Single-look complex (SLC)
Quad polarization
[F], [S], [W]

4 x [C16S] raster channels (uncalibrated)
—or—
4 x [C32R] raster channels (calibrated)

1 x [GCP] ground control points
1 x [TEX] main product annotation
1 x [ORB] orbit segment
1 x [BIN] rational function model segment
1 x [ARR] incidence angle array

Data can be calibrated in sigma, beta, or gamma nought.

• (SGX), (SGF)
Single polarization
[SLA]
[U], [MF], [F], [S], [W], [EH], [EL]

• (SCN), (SCW), (SCF), (SCS)
Single polarization
[SCN], [SCW], [DVWF], [OSVN]

1 x [16U] raster channel (uncalibrated)
—or—
1 x [32R] raster channel (calibrated)

1 x [GCP] ground control points
1 x [TEX] main product annotation
1 x [ORB] orbit segment
1 x [BIN] rational function model segment
1 x [ARR] incidence angle array

Data can be calibrated in sigma, beta, or gamma nought.

• (SGX), (SGF)
Dual polarization
[F], [S], [W]

• (SCN), (SCW), (SCF), (SCS)
Dual polarization
[SCN], [SCW], [OSVN]

2 x [16U] raster channels (uncalibrated)
—or—
2 x [32R] raster channels (calibrated)

1 x [GCP] ground control points
1 x [TEX] main product annotation
1 x [ORB] orbit segment
1 x [BIN] rational function model segment
1 x [ARR] incidence angle array

Data can be calibrated in sigma, beta, or gamma nought.

(SGX)
Quad polarization
[FQ], [SQ]

4 x [16U] raster channels (uncalibrated)
—or—
4 x [32R] raster channels (calibrated)

1 x [GCP] ground control points
1 x [TEX] main product annotation
1 x [ORB] orbit segment
1 x [BIN] rational function model segment
1 x [ARR] incidence angle array

Data can be calibrated in sigma, beta, or gamma nought.

Quad-polarization data is not distributed in SGF.

To conduct a polarimetric analysis, you must have SLC data.

References

RADARSAT-2 Product Description. MacDonald, Dettwiler and Associates Ltd. RN-SP-52-1238. Issue 1/13: March 21, 2016.

RADARSAT-2 NITF 2.1 Product Format Definition. MacDonald, Dettwiler and Associates Ltd. RN-SP-52-8207. Issue 2/1: May 22, 2015.

RADARSAT-2 Product Format Definition. MacDonald, Dettwiler and Associates Ltd., , RN-RP-51-2713, Issue 1/5. November 24, 2003.

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