Please tell me.
I tried to perform GPT processing with SNAP, but the analysis speed is significantly slower compared to manual analysis. It takes about four times as long as when analyzed manually. The maximum memory usage for the SNAP main body is set to 32GB. However, when performing analysis with GPT, I can only achieve analysis speeds similar to when limiting the memory to 8GB. Is there a way to configure the memory settings used during GPT processing?
Thank you.
I am processing Sentinel-1 SLC images to get PolSARPro output format using the gpt command line.
This is the workflow I am using:
Read > TOPSAR-Split > Apply-Orbit-File > Calibration > TOPSAR-Deburst > Polarimetric-Speckle-Filter > Terrain-Correction > Write
I have tested the output after every step and compared it to the output when using the SNAP GUI. Everything works well until the “Write” step.
When I export the output of the ‘Terrain-Correction’ using the GUI, it works fine. I also tested using a read > write graph, and it also works fine. However, when I use the command prompt to write the output file to PolSARPro format, the values are all 0, although the file size is similar to the output from the GUI.
Here is what I did:
################## Terrain-Correction
Stage7: run “cd d:\snap_cmd\terrain_correction_iw1_output”
Stage7b: run “gpt Terrain-Correction -Ssource=D:\snap_cmd\pol_speckle_filter_iw1_output\target.dim -PpixelSpacingInDegree=8.983153E-5 -PpixelSpacingInMeter=10”
################## Write
Stage8: run “cd d:\snap_cmd\write_iw1_output”
Stage8: run “gpt Write -Ssource=D:\snap_cmd\terrain_correction_iw1_output\target.dim -Pfile=D:\snap_cmd\write_iw1_output\S1B_IW_SLC__1SDV_20210613T004848_20210613T004915_027331_0343A9_3F05_proc_iw1 -PformatName=‘PolSARPro’”
This command reads the product from D:\snap_cmd\terrain_correction_iw1_output\target.dim and writes it to D:\Hansanee_PhD\s1_cmd_process\snap_output\target.hdr in PolSARPro format.
Despite the correct file size, the values are all 0 when using the command line. How can I resolve this issue?