Terrain-Flattening "Output Simulated Image" fails for S1 SLCs

johntruckenbrodt · September 19, 2022, 9:40am

Currently the simulated image can only be created from S1 GRD images. The following error occurs when processing SLCs:

Likely the following line is causing trouble:

senbox-org/s1tbx/blob/a78d79745e1629dafaf922708e1e4cc8f64f5f14/s1tbx-op-sar-processing/src/main/java/org/esa/s1tbx/sar/gpf/geometric/TerrainFlatteningOp.java#L812

      
        
                                                 final Map<Band, Tile> targetTiles) throws Exception {
            
            
        final Tile targetTile = targetTiles.get(targetBand);
                    final ProductData targetData = targetTile.getDataBuffer();
                    final TileIndex tgtIndex = new TileIndex(targetTile);
            
            
        for (int y = y0; y < y0 + h; y++) {
                        final int yy = y - y0;
                        tgtIndex.calculateStride(y);
                        final double zeroDopplerTime = firstLineUTC + y*lineTimeInterval;
                        final double[] srgrCoeff = SARGeocoding.getSRGRCoefficients(zeroDopplerTime, srgrConvParams);
            
            
            for (int x = x0; x < x0 + w; x++) {
                            final int xx = x - x0;
                            final int tgtIdx = tgtIndex.getIndex(x);
                            double simVal = simulatedImage[yy][xx];
                            if (simVal != noDataValue && simVal != 0.0) {
                                simVal /= aBeta;
                                if (isGRD) {
                                    simVal /= computeSRGRRatio(x, srgrCoeff);
            //                        simVal /= FastMath.sin(incidenceAngleTPG.getPixelDouble(x, y) * Constants.DTOR);

jun_lu · September 19, 2022, 6:47pm

A JIRA ticket ([SITBX-926] - JIRA) has been created to track the issue. We will look into it, thank you for reporting the problem.

jun_lu · September 19, 2022, 6:51pm

The issue has been fixed and the fix should be in the next patch release. Thank you