Ocean object detection with COSMO-SkyMed

I am performing an ocean object detection using COSMO-SkyMed stripmap data
Despite Sentinel-1 is processed, I cannot execute the operation over a COSMO-SkyMed stripmap image, even if image dimension is not big (less then 200 MB) and I have already converted .h5 image into .dim format.

I am using SNAP 5.0, will with a previous version (I thing SNAP 3) I could execute the processing.

I always obtain “java.lang.StackOverflowError” error, with both gpt processor using a graph, and throug SNAP GUI

Thanks for tour help

which pre-processing did you apply on your data?

I Abraun, thanks for your reply.

I first saved the .h5 image in BEAM-DIMAP format, then subset the image. At the end, I used the Ocean object detection tool as implemented in SNAP GUI.

But investigating the possible causes, I noticed that with smaller windows in the Adaptive Thresolding step the workflow ends with no error.

So I think that the problem is that using big windows (e.g. 800 m for background window size and so on as default options) causes the operator to build too big stacks, giving the error. With Sentinel-1 I did not obtain the error perhaps because at the same window dimension correspond a smaller number of pixels (due to the 20 m pixel size of Sentinel-1 GRD).

Could it be a possible solution to increase Java stack memory, adding a -Xss option in the VM performance options tab?
Do you have any other suggestions?

Thank you

I personally would calibrate to Beta0 first, but this is probably not the error source.
The fact that larger window sizes produce a result indicates that it’s somehow the algorithm which caused the error.
Increasing the available memory is always a good choice to prevent errors but I’m not very firm with the Java variables. You’ll find some answers in here using the search.

1 Like

When should Beta0 or Sigma0 be used?

Beta0 doesn’t need information on the incidence angle. As you are working on flat water areas it should be sufficient.
Please anyone correct my if I’m wrong.

What do you mean? is that necessary to make this conversion? how do you do it?

Many Thanks

each file processed in SNAP is stored as a .dim-format by default. This handles the metadata best (instead of GeoTiff for example).
If there is nothing else to process, you can at least make a subset or calibrate your product.