Hi SNAP, I used to compute Coherence between two Sentinel-1 images following this S1TBX Tutorial using this graph attached. However, even for small areas this takes very long computation because it loads full images and then debursts.
I later discovered that ASF provides single bursts, but the graph does not work anymore, it gives an error saying that the input is not a SAR product. How should I perform Coherence between two S1 Bursts?
Thanks
s1coherence.xml (7.3 KB)
Coherence between S-1 bursts can be obtained using the ASF On Demand processing service. This is a free, cloud-based service available through Vertex Data Search, or programmatically using the HyP3 SDK or HyP3 API.
Information on the ISCE2-based burst processing service is available in the Product Guide:
General information on the ASF On Demand processing service is available in the user guide:
Thank you for the info. What about SNAP? Is it possible reading ASF bursts as SAR products in SNAP?
Thanks
No. SNAP supports official Copernicus S-1 products and their single-burst product once it becomes operational.
It’s incorrect because SNAP supports SAFE format scenes independently of their origin. You can try these options:
NASA ASF team provided burst downloading tool to download individual bursts and convert them to common SAFE scenes: GitHub - forrestfwilliams/burst2safe: A package for converting ASF-derived Sentinel-1 burst SLC products to the ESA SAFE format
PyGMTSAR (Python InSAR) provides bursts downloading module to save them as single burst SAFE scenes.
SAFE-format itself does not guarantee that all metadata required by SNAP is correctly in place, so compatibility cannot be guaranteed a priori.
There are only two files required for InSAR processing (GeoTIFF and XML). These include radar measurements, approximate orbit, geolocation points to preview the area, and more. If SNAP looks for anything more, it is a bug.
@mengdahl What approach do you suggest to generate a time series of S-1 IW SLC data spanning the period before and after the date the area covered by each slice changed?
Happy to see the Sentinel-1 SLC burst data access now operational in the Copernicus Data Space Ecosystem (Documentation - Sentinel-1 SLC Bursts) and happy to know that SNAP can support that!
I was trying to use this new burst access capability in CDSE and trying to import the extracted bursts in SNAP. Indeed, SNAP appears to read these bursts correctly; however, I encountered some issues when attempting to run some processing on them. Please check the description of the issue I found in this post I just published:
Could it be a problem on how the burst metadata are extracted in the CDSE tool or how they are read in SNAP?