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<< Click to Display Table of Contents >> ScanSAR Interferometry Module - 1 - Interferogram Generation |
  
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<< Click to Display Table of Contents >> ScanSAR Interferometry Module - 1 - Interferogram Generation |
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Purpose
A flattened interferogram can be generated from a ScanSAR pair
This module can be used for TerrasarX ScanSAR and Palsar-2 ScanSAR (full aperture SLC products) data.
Technical Note
Due to data separation into bursts, ScanSAR interferometry requires "ad-hoc" steps to consider overlap and different parameters between data sub-swaths. In particular timing and phase/magnitude compensation at the bounds of bursts and swaths have to be managed in order to avoid phase discontinuities or other undesired artifacts. These parameters are automatically taken into account during this processing step.
Input Files
Digital Elevation Model File
Name of the Digital Elevation Model file. This should be referred to the ellipsoid. This file is optional. In case it is omitted, the ellipsoidal height and the relevant cartographic reference system, must be entered.
Input Reference File
The file name is the _slc_list. This file is mandatory.
Input Secondary File
The file name is the _slc_list. This file is mandatory.
Output Root Name
Name of the output root. This file is mandatory.
DEM/Cartographic System
Digital Elevation Model file
Digital Elevation Model file name. This should be referred to the ellipsoid. In case a list of input files is entered, the DEM must cover the whole imaged area. This file is optional.
Output Projection
In case that the Digital Elevation Model is not used, it is mandatory to define the Cartographic System.
To use the same coordinate system as another dataset, click the Import from Existing Dataset button and select the source dataset.
To apply the same Coordinate System of the current selected layer
The reset icon allows to reset the coordinate system field.
Parameters - Principal Parameters
Data Type
The sensor used has to be chosen between the following options:
- PALSAR - Full aperture method, if Palsar 2 ScanSAR data are used, the other parameters could be changed by the user.
- TerraSAR-X_SC, if TerraSAR data are used. The number of looks is automatically chosen.
Azimuth Looks
Number of looks in azimuth (PALSAR only).
Range Looks
Number of looks in range (PALSAR only).
Grid Size for Suggested Looks
The grid size, in meters, used to tune range and azimuth looks. If the other parameters are manually set, the grid size will not imply a change in their values (PALSAR only).
Parameters - Global
It brings to the general section of the Preferences parameters. Any modified value will be used and stored for further processing sessions.
Parameters - Flattening
It brings to the flattening section of the Preferences parameters. Any modified value will be used and stored for further processing sessions.
Parameters - Coregistration
It brings to the coregistration section of the Preferences parameters. Any modified value will be used and stored for further processing sessions.
Parameters - Other Parameters
It brings to the general section of the Preferences parameters. Any modified value will be used and stored for further processing sessions.
Output Files
Output Root Name
Name of the output root. This file is mandatory.
_int
Interferogram with the associated header files (.sml, .hdr).
_dint
Flattened interferogram with the associated header files (.sml, .hdr).
_dint_ql.tiff and/or _dint_qlt.tiff
Tiff image of the flattened interferogram. The creation of these files depends on the selection of "quick look format" in the parameters. It uses a cyclic color scale ranging from -pi to +pi which is reported here below:
_sint
Synthetic phase with the associated header files (.sml, .hdr).
_srdem
Digital Elevation Model, in slant range geometry, with the associated header files (.sml, .hdr).
_slc_rsp
Coregistered Single Look Complex data. This file is generated only if the relevant flag is set.
_par
ASCII file containing the coregistration shift parameters in range and azimuth. This file is generated only if the shift parameters are calculated.
_pwr
Multi-looked Reference and Secondary image with the associated header files (.sml, .hdr).
_orb.sml
Xml file containing the scene orbital parameters.
_orbit_off.shp
Shape file with the points used to estimate the orbit based shift. This file contains the following information:
| - | Pixel position in range direction (Range), in Single Look pixel units. |
| - | Pixel position in azimuth direction (Azimuth), in Single Look pixel units. |
| - | Shift measured in range direction (Dr), in Single Look pixel units. |
| - | Shift measured in azimuth direction (Da), in Single Look pixel units. |
| - | Calculated polynomial shift, to apply in range direction (Drfit), in Single Look pixel units. |
| - | Calculated polynomial shift, to apply in azimuth direction (Dafit), in Single Look pixel units. |
The file, which is generated only when the shift parameters are calculated, is multilooked (i.e. Azimuth and Range looks) as specified in the Input Parameters.
_winCC_off.shp
Shape file with the points used to estimate the cross correlation based shift from the Intensity data. In addition to the information provided by the "_orbit_off.shp" file, this file contains also the cross-correlation value (CC), which is dimensionless and it can vary from 0 to 1.
The file, which is generated only when the shift parameters are calculated, is multilooked (i.e. Azimuth and Range looks) as specified in the Input Parameters.
_winCoh_off.shp
Shape file with the points used to estimate the coherence based shift from the complex data (fine shift estimate). In addition to the information provided by the "_orbit_off.shp", this file contains also the following information:
| - | Signal to Noise Ratio (SNR), which is a linear dimensionless value. |
| - | Coherence value. It is dimensionless and it can vary from 0 to 1. |
The file, which is generated only when the shift parameters are calculated, is multilooked (i.e. Azimuth and Range looks) as specified in the Input Parameters.
Details specific to the Units of Measure and Nomenclature of the output products can be found in the Data Format section.
General Functions
Exec
The processing step is executed.
Store Batch
The processing step is stored in the batch list. The Batch Browser button allows to load the batch processing list.
Close
The window will be closed.
Help
Specific help document section.
Specific Function(s)
| None. |
Task, SARscapeBatch object, SARscapeBatch script example
References Monti Guarnieri A., P. Guccione, P. Pasquali, and Y.L. Desnos: "Multi-mode ENVISAT ASAR interferometry: Techniques and preliminary results, IEEE Proceedings on Radar, Sonar and Navigation, Vol. 150, No. 3, June, 2003.