Hi all
I’m trying to follow the steps of the Sentinel-1 Toolbox TOPS Interferometry Tutorial:
My problem is that it doesn’t seem to be working properly the generation of the unwrapped phase…
I have read the following posts:
But the problem is that I have no .img file generated when I’m going to import the unwrapped phase.
I show my the steps, one by one:
I think that unwrapping was “too fast”, according to the Figure 23 (“Progress of the unwrapping”) of the tutorial.
Thanks in advance!!
can you please check in the snaphu folder if the img file of the unwrapped phase was created?
To import the unwrapped phase into SNAP, you need both
The second is produced by SNAPHU. If it was not created, try executing snaphu from the command line instead from inside SNAP.
Hi Andreas
I checked and img file of the unwrapped phase was not created… only the hdr file.
These are the steps I’m following:
Exporting alone is not enough. You have to run snaphu as well, as it is described in the tutorial, either from the command line or within SNAP
This will create the img file.
Thank you for your patience Andreas:
I managed to unwrapp and then, import the unwrapped phase, but now the problem is that:
The Phase to Desplacement tool doesn’t work.
This is the log file:
messages.log (163.2 KB)
It would seem that the error concerns to the projection, but I don´t know how to do:
“Source product should not be map projected” already says it.
Terrain correction should be the very last step. Please follow the steps in the order as they are presented in the tutorial.
The problem (I think) is that I was checking the option “save Wrapped interferogram in the target product”. I solved it but now I have this message:
thank you for sharing with us
Maybe it needs to be the metadata from the original product and not the subset product because its size would be different. Given that I don’t know how to set the metadata, I will try to do the unwrapping process with original the image (without subset).
exactly this is done with the SNAPHU import. You select the reference product (interferogram) in SNAP, also the unwrapped interferogram in the second.
The product should therefore no longer be named “UnwPhase”, but again starting with “subset_S1A…”. Please stick to the order of the tutorial.
I discovered that sometime snaphu can stop to unwrap, and seems to be linked with a bad coregistration or low coherence product
How did you manage to solve this.
How do you run and export at the same time in snap. i am facing the ssame dificulty.
Why does SNAP sometimes fail to create a .img file even when I follow every tutorial step? Is it related to input data or some problem within the software itself?
Please provide more details about your problem. See STEP Forum FAQ - Read This Before Posting - How to report an issue
Hello, I’m encountering an error while running the Snaphu unwrapping process.
I have attempted several trials using different parameters during Snaphu export and also tried filtering low coherence areas, but the results remain unchanged.
snaphu v2.0.4
27 parameters input from file snaphu.conf (84 lines total)
WARNING: Tile overlap is small (may give bad results)
Logging run-time parameters to file snaphu.log
Creating temporary directory snaphu_tiles_1113
Unwrapping tile at row 0, column 0 (pid 1114)
Unwrapping tile at row 0, column 1 (pid 1115)
Unwrapping tile at row 0, column 2 (pid 1116)
Unexpected or abnormal exit of child process 1114
Abort
Unwrapping tile at row 0, column 3 (pid 1117)
Exiting with status 1 on signal 15
Process exited with value 1
Finished tool execution in 4 seconds
Process exited with value 1
Finished tool execution in 1 secondssnaphu v2.0.4
27 parameters input from file snaphu.conf (84 lines total)
WARNING: Tile overlap is small (may give bad results)
Logging run-time parameters to file snaphu.log
Creating temporary directory snaphu_tiles_1113
Unwrapping tile at row 0, column 0 (pid 1114)
Unwrapping tile at row 0, column 1 (pid 1115)
Unwrapping tile at row 0, column 2 (pid 1116)
Unexpected or abnormal exit of child process 1114
Abort
Unwrapping tile at row 0, column 3 (pid 1117)
Exiting with status 1 on signal 15
Process exited with value 1
Finished tool execution in 4 seconds
Process exited with value 1
Finished tool execution in 1 seconds
It seems you’re trying to unwrap a raster that’s too large. Try adjusting your SNAPHU tiles to be about 1500 pixels per dimension, and you’ll be able to unwrap larger rasters. Alternatively, you can reduce the processing resolution. This online interactive example can process two stitched Sentinel-1 scenes on just 2GB of RAM by using the proper resolution and SNAPHU tiling:
