NPE in Range Doppler Terrain Correction (S1A)

Microwave Toolbox Problem Reports
#1

With SNAP 8.0.3, I’m trying to apply range doppler terrain correction (DEM: Copernicus 30m Global) on a subset of

S1A_EW_GRDM_1SSH_20210513T011016_20210513T011128_037862_0477FD_FE40

and face the following errors when running the process:

java.lang.NullPointerException
	at org.esa.snap.core.gpf.internal.OperatorImageTileStack.computeRect(OperatorImageTileStack.java:134)
	at org.esa.snap.core.gpf.internal.OperatorImageTileStack.computeTile(OperatorImageTileStack.java:86)
	at com.sun.media.jai.util.SunTileScheduler.scheduleTile(Unknown Source)
	at javax.media.jai.OpImage.getTile(Unknown Source)
	at javax.media.jai.PlanarImage.getData(Unknown Source)
	at com.bc.ceres.glevel.MultiLevelImage.getData(MultiLevelImage.java:64)
	at org.esa.snap.core.gpf.internal.OperatorContext.getSourceTile(OperatorContext.java:449)
	at org.esa.snap.core.gpf.internal.OperatorContext.getSourceTile(OperatorContext.java:435)
	at org.esa.snap.core.gpf.internal.OperatorImage.computeRect(OperatorImage.java:75)
[catch] at javax.media.jai.SourcelessOpImage.computeTile(Unknown Source)
	at com.sun.media.jai.util.SunTileScheduler.scheduleTile(Unknown Source)
	at javax.media.jai.OpImage.getTile(Unknown Source)
	at com.sun.media.jai.util.RequestJob.compute(Unknown Source)
	at com.sun.media.jai.util.WorkerThread.run(Unknown Source)

java.lang.IllegalStateException: GeoTiff imageReader not found.
	at org.esa.snap.dataio.geotiff.GeoTiffImageReader.findImageReader(GeoTiffImageReader.java:270)
	at org.esa.snap.dataio.geotiff.GeoTiffImageReader.buildImageReader(GeoTiffImageReader.java:251)
	at org.esa.snap.dataio.geotiff.GeoTiffImageReader.<init>(GeoTiffImageReader.java:85)
	at org.esa.snap.dataio.geotiff.GeoTiffImageReader.buildGeoTiffImageReader(GeoTiffImageReader.java:327)
	at org.esa.snap.dataio.geotiff.GeoTiffImageReader.buildGeoTiffImageReader(GeoTiffImageReader.java:298)
	at org.esa.snap.dataio.geotiff.GeoTiffProductReader.readProductNodesImpl(GeoTiffProductReader.java:121)
	at org.esa.snap.core.dataio.AbstractProductReader.readProductNodes(AbstractProductReader.java:178)
	at org.esa.snap.core.dataop.dem.ElevationFile.getLocalFile(ElevationFile.java:136)
	at org.esa.snap.core.dataop.dem.ElevationFile.getFile(ElevationFile.java:103)
	at org.esa.snap.core.dataop.dem.ElevationFile.getTile(ElevationFile.java:83)
	at org.esa.snap.core.dataop.dem.BaseElevationModel.getSamples(BaseElevationModel.java:161)
	at org.esa.snap.core.dataop.resamp.BilinearInterpolationResampling.resample(BilinearInterpolationResampling.java:82)
	at org.esa.snap.core.dataop.dem.BaseElevationModel.getElevation(BaseElevationModel.java:99)
	at org.esa.snap.dem.dataio.DEMFactory.getLocalDEM(DEMFactory.java:182)
	at org.esa.s1tbx.sar.gpf.geometric.RangeDopplerGeocodingOp.computeTileStack(RangeDopplerGeocodingOp.java:861)
Caused: org.esa.snap.core.gpf.OperatorException: GeoTiff imageReader not found.
	at org.esa.snap.engine_utilities.gpf.OperatorUtils.catchOperatorException(OperatorUtils.java:440)
	at org.esa.s1tbx.sar.gpf.geometric.RangeDopplerGeocodingOp.computeTileStack(RangeDopplerGeocodingOp.java:1067)
	at org.esa.snap.core.gpf.internal.OperatorImageTileStack.computeRect(OperatorImageTileStack.java:122)
	at org.esa.snap.core.gpf.internal.OperatorImageTileStack.computeTile(OperatorImageTileStack.java:86)
Caused: org.esa.snap.core.gpf.OperatorException: GeoTiff imageReader not found.
	at org.esa.snap.core.gpf.internal.OperatorExecutor$GPFImagingListener.errorOccurred(OperatorExecutor.java:381)
	at com.sun.media.jai.util.SunTileScheduler.sendExceptionToListener(Unknown Source)
	at com.sun.media.jai.util.SunTileScheduler.scheduleTile(Unknown Source)
	at javax.media.jai.OpImage.getTile(Unknown Source)
	at javax.media.jai.PlanarImage.getData(Unknown Source)
	at com.bc.ceres.glevel.MultiLevelImage.getData(MultiLevelImage.java:64)
	at org.esa.snap.core.gpf.internal.OperatorContext.getSourceTile(OperatorContext.java:449)
	at org.esa.snap.core.gpf.internal.OperatorContext.getSourceTile(OperatorContext.java:435)
	at org.esa.snap.core.gpf.internal.OperatorImage.computeRect(OperatorImage.java:75)
	at javax.media.jai.SourcelessOpImage.computeTile(Unknown Source)
	at com.sun.media.jai.util.SunTileScheduler.scheduleTile(Unknown Source)
	at javax.media.jai.OpImage.getTile(Unknown Source)
	at com.sun.media.jai.util.RequestJob.compute(Unknown Source)
[catch] at com.sun.media.jai.util.WorkerThread.run(Unknown Source)

image
image1506×1410 703 KB

Am I doing something wrong? I’m new to SAR processing.

#2

What does the DEM look like in that area? (I don’t know how ocean/ice shelves are treated in it). In any case using the DEM, even if empty should not give you that error.

Meanwhile you can try ellipsoid geocoding which precesses everything as if everything was on the reference ellipsoid.