SARCalibration¶
Perform radiometric calibration of SAR images. Following sensors are supported: TerraSAR-X, Sentinel1 and Radarsat-2.Both Single Look Complex(SLC) and detected products are supported as input.
Description¶
The objective of SAR calibration is to provide imagery in which the pixel values can be directly related to the radar backscatter of the scene. This application allows computing Sigma Naught (Radiometric Calibration) for TerraSAR-X, Sentinel1 L1 and Radarsat-2 sensors. Metadata are automatically retrieved from image products.The application supports complex and non-complex images (SLC or detected products).
Parameters¶
Input Image -in image Mandatory
Input complex image
Output Image -out image [dtype] Mandatory
Output calibrated image. This image contains the backscatter (sigmaNought) of the input image.
Disable Noise -noise bool Default value: false
Flag to disable noise. This parameter is deprecated , it has the opposite effect of removenoise, which should be preferred to this parameter.
Remove Noise -removenoise bool Default value: false
Remove the noise of the input product. The type of noise and the denoising method depends on the input sensor. The following sensors are supported:
- Sentinel 1: Remove thermal noise using the denoising LUTs according to [1]
- TerraSAR-X: Noise Equivalent Beta Nought computation [2], see the application limitations
Lookup table -lut [sigma|beta|gamma|dn] Default value: sigma
Lookup table values are not available with all SAR products. Products that provide lookup table with metadata are: Sentinel1, Radarsat2.
- Use sigma nought lookup
Use Sigma nought lookup value from product metadata - Use beta nought lookup
Use Beta nought lookup value from product metadata - Use gamma nought lookup
Use Gamma nought lookup value from product metadata - Use DN value lookup
Use DN value lookup value from product metadata
Available RAM (MB) -ram int Default value: 256
Available memory for processing (in MB).
Examples¶
From the command-line:
otbcli_SARCalibration -in RSAT_imagery_HH.tif -out SarRadiometricCalibration.tif
From Python:
import otbApplication
app = otbApplication.Registry.CreateApplication("SARCalibration")
app.SetParameterString("in", "RSAT_imagery_HH.tif")
app.SetParameterString("out", "SarRadiometricCalibration.tif")
app.ExecuteAndWriteOutput()
Limitations¶
The implementation of TerraSAR-X denoising is still experimental. The results have not been validated recently, see OTB issue #2158