Problem with S-1 TOPS Deburst function - java error


I am a beginner user of ESA SNAP 6.0. So far I proceed with Sentinel 2 images and now I try to process Sentinel 1 SAR data.
So I downloaded S1B_IW_SLC_1SDV file from Copernicus Hub. Processes I performed:

  1. Opened the product with SNAP 6.0
  2. Deleted all IW2 and IW3 products (I need only IW1).
  3. Performed resampling (just to make the next step possible)
  4. Used the “subset spatial from view” function from the resampled product to work out only on data of the small farm field.
  5. Performed calibration.
    And then I wanted to perform speckle filtering or polarimetric operation, but ESA SNAP want me to perform debursting first.
    When I try to deburst the image (via S-1 TOPS Deburst function) an error occurs:

A problem occurred during the target product initialisation.
Type: OperatorException
Message: java.lang.NullPointerException

What do you think causes the error? Is it something with sequence of processes above, hardware problem (I have 8GB RAM), or something else? Sorry if I did something stupid.

Thank you in advance for your help.
Best regards, Wojciech.

Perhaps that happened because you deleted IW2 and IW3 manually. Use TOPS Split to get the swath you want and then deburst.

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instead of deleting swaths which are not required you can use the TOPS Split module. This allows you to define the swath and bursts which are written in a seperate product.
Not sure if this caused the java error but it’s the better way to handle SLC data in general.

If you don’t need phase information you can also just download the GRD product instead of the SLC. They are quite ready to use and require less pre-processing.

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Thank you very much for your help. You’re right – using the TOPS Split function at first solved the problem.
Also I read and apply helpful tips from this topic: TOPS "Create Subset"

I decided to use SLC data because of better spatial resolution and also to make familiar with polarization processing. My target is to learn how to identify different types of crops on the farm field, but I need to learn some more SAR theory first – I see it’s much more complicated than optical imaging.

Could you please help me with one more issue? According to this Polarimetric Tutorial ( I should use Matrix Generation operator after calibration. The process can’t start because of the error: “Full-pol polarimetric product is expected”. I understand that I am missing of HV and HH polarization data? Originally I had only VH and VV bands. What kind of Sentinel 1 data should I download to learn how to process polarimetric operations correctly? Can I use GRD products for this?

Thanks once again, have a good day,

Dear Wojciech, unfortunately, Sentinel-1 only has 2 polarizations. Quad-pol operations cannot be applied on S1 data.
Maybe this helps you:

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Thank you for your answer and references.

In that case, can I ask you what operations would you recommend to achieve image like on attached screenshot? It’s from “” website. I would like to make it useful for agriculture.

Thank you!

AGRISAR is a airborne SAR system with quad-polarized c-band data. It can hardly be compared to Sentinel-1, regarding resolution and polarization quantity.

When you want to monitor crops with S1, you should stick to the dual polarized data at least and try to use time-series of multiple scenes in order to get information on the temporal development of areas. Maybe also the dual decomposition mentioned above is helpful.

Thank you for your help.
Best regards,