Subsetting before Terrain Correction fails with SNAP 13 (almost sure it was working with SNAP12), both with the Subset Operator and with the advanced options in Read.
Command line :
gpt "D:\grd_s1_preprocess_default.xml" -Pfile="D:\S1B_IW_GRDH_1SDV_20191215T180300_20191215T180325_019379_0249B2_C99C.SAFE" -Pvector_file="geo_region.shp" -Pdem_name="Copernicus 30m Global DEM" -Pcrs
=EPSG:32630 -Pres_m=0.0 -Pres_deg=0.0 -Pout="D:\20191215T180300_S1_VV_VH_IW_GRD.dim"
Graph :
<graph id="Graph">
<version>1.0</version>
<node id="Read">
<operator>Read</operator>
<sources/>
<parameters class="com.bc.ceres.binding.dom.XppDomElement">
<file>${file}</file>
<formatName>SENTINEL-1</formatName>
<useAdvancedOptions>true</useAdvancedOptions>
<copyMetadata>true</copyMetadata>
<vectorFile>${vector_file}</vectorFile>
</parameters>
</node>
<node id="Terrain-Correction">
<operator>Terrain-Correction</operator>
<sources>
<sourceProduct refid="Read"/>
</sources>
<parameters class="com.bc.ceres.binding.dom.XppDomElement">
<sourceBands/>
<demName>${dem_name}</demName>
<externalDEMFile>${dem_path}</externalDEMFile>
<externalDEMNoDataValue>0.0</externalDEMNoDataValue>
<externalDEMApplyEGM>true</externalDEMApplyEGM>
<demResamplingMethod>BILINEAR_INTERPOLATION</demResamplingMethod>
<imgResamplingMethod>BILINEAR_INTERPOLATION</imgResamplingMethod>
<pixelSpacingInMeter>${res_m}</pixelSpacingInMeter>
<pixelSpacingInDegree>${res_deg}</pixelSpacingInDegree>
<mapProjection>${crs}</mapProjection>
<nodataValueAtSea>false</nodataValueAtSea>
<saveDEM>false</saveDEM>
<saveLatLon>false</saveLatLon>
<saveIncidenceAngleFromEllipsoid>false</saveIncidenceAngleFromEllipsoid>
<saveLocalIncidenceAngle>false</saveLocalIncidenceAngle>
<saveProjectedLocalIncidenceAngle>false</saveProjectedLocalIncidenceAngle>
<saveSelectedSourceBand>true</saveSelectedSourceBand>
<saveLayoverShadowMask>false</saveLayoverShadowMask>
<outputComplex>false</outputComplex>
<applyRadiometricNormalization>false</applyRadiometricNormalization>
<saveSigmaNought>false</saveSigmaNought>
<saveGammaNought>false</saveGammaNought>
<saveBetaNought>false</saveBetaNought>
<incidenceAngleForSigma0>Use projected local incidence angle from DEM</incidenceAngleForSigma0>
<incidenceAngleForGamma0>Use projected local incidence angle from DEM</incidenceAngleForGamma0>
<auxFile>Latest Auxiliary File</auxFile>
<externalAuxFile/>
</parameters>
</node>
<node id="LinearToFromdB">
<operator>LinearToFromdB</operator>
<sources>
<sourceProduct refid="Terrain-Correction"/>
</sources>
<parameters class="com.bc.ceres.binding.dom.XppDomElement">
<sourceBands/>
</parameters>
</node>
<node id="Write">
<operator>Write</operator>
<sources>
<sourceProduct refid="LinearToFromdB"/>
</sources>
<parameters class="com.bc.ceres.binding.dom.XppDomElement">
<file>${out}</file>
<formatName>BEAM-DIMAP</formatName>
</parameters>
</node>
</graph>
Vector file : geo_region.zip (895 Bytes)
The vector is within the S1 extent :
Result : empty file
Executing processing graph
....12%...24%...36%...48%...60%...72%...84%..WARNING: eu.esa.sar.sar.gpf.geometric.RangeDopplerGeocodingOp: Terrain-Correction error: no valid output was produced. Please verify the DEM
done.
____
Other tests gave me other strange results, also with geometryRegion
Some examples:
- other subsetting polygon in green, very strange result
- Wrong orthorectification : the image is shifted (a lot)
Maybe linked to: Graph Builder Subset and Terrain Correction Error Sentinel 1 - #41 by Boorhin