PALSAR-2 ScanSAR processing in SNAP


Does currently S1TBX support DInSAR processing of PALSAR-2 ScanSAR?

When I imported VOL file with File/Import/SAR Sensors/ ALOS 2 CEOS, I got following error message: [input=D:\VOL-ALOS2014341350-140829-WBDR1.1__A]: _sceneWidth == imageFile[1].getRasterWidth()

Many thanks

All I can say is it might? I haven’t seen enough data to have tried it
myself. If you run into some problems and can share your data then we
could to try to fix the issues.


I get the same error message opening a PALSAR-2 ScanSAR Level1.1 in the Snap toolbox (4.0.2/S1TBX4.0.3):
[input=E:\XXXX\VOL-ALOS2075181950-151014-WBDR1.1__D]:_sceneWidth == imageFile[1].getRasterWidth()

Will this problem be resolved in future releases?


I got the same error here. Wonder how to solve it?




I would like to share my data with you to see if you have a chance to fix the problem of reading ALOS2 scansar data. However, the file size is huge like 30Gb. Could you let me know how I can deliver the ALOS2 scansar data to you?



ALOS2 ScanSAR data is not supported by SNAP. I can update the reader to at least read in the subswaths properly but, then we’ll need to support the burst data properly and this won’t be trivial.

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Thanks Luis.

I recognize that we could either acquire burst or full-aperture L1.1 SLC. Will a full-aperture file type help?

I also found that a full-aperture file is splitting of scan (similar to TOPSAR), whereas burst files are more complicated.

Hi lveci,

I imported ALOS-2 PALSAR-2 ScanSAR (WD1) )( 100 m, 350 km swath) at Level 1.5 and it worked fine. The issue is with the terrain correction…

Have you tried processing the Level 1.1 data (ALOS-2 ScanSAR, 100 m, 350 km swath)? Do you happen to know if importing (and processing) is do-able in SNAP 5.0 and if there are any issues with it?

Help greatly appreciated!! Thank you.

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I have some images from ALOS PALSAR 2, level 1.1, dual-pol, fine mode and I believe that the processing steps is different from Sentinel-1, SLC. Could you please give me some information about how could I make the processing of this data in SNAP? My research is to characterize deforestation in Amazonia rain forest. Thanks in advance.

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Sentinel-1 SLC are acquired in TOPS mode which is significantly different than the (more common) stripmap mode.

ALOS L1.1 corresponds to a slant range complex (SLC) image but you need TOPS Deburst only for Sentinel-1 data (and ENVISAT WideBeam).
Calibration is advisable if you work with multiple images so they become comparable.
Then use multi-looking to retrieve square pixels (check how the final resolution changes with increasing number of looks). Image quality will become significantly better but for the cost of lower spatial resolution.
As a last step, apply Range Doppler Terrain Correction and select a target coordinate reference system.

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Thank you!

Just to check if I am doing the correct steps of processing of Sentinel-1, SLC, IW, dual-pol image: orbit file – calibration – deburst – multilooking – terrain correction - dB.

Thank s for your help.

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Is this correct?

basically yes. Sometimes, thermal noise is in the SLC data which should be removed in a first step. Have a look here: Radiometric & Geometric Correction Workflow

Thermal noise can be only removed after detection, in other words from amplitude/intensity images.

good to know, thank you. I changed the proposed pre-processing steps.

If I remember correctly it’s possible to “calibrate” i and q but technically speaking that is not the correct approach.

So, does it mean that thermal noise should be applied after multilooking?
How would be the final pre-processing steps?

Thank you very much,

I do not think PALSAR provides thermal noise information, so that processing step would be unnecessary.