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S1 TOPS-mode SLC data processing
Added by Kendall Wnuk about 9 years ago
Hi all,
Im having difficulty understanding the Sentinel 1 preprocessing chain.
I have two scenes of Wide Swath Sentinel 1 data, one from 7/31/2015 and one from 8/24/2015, which I am trying to use as inputs for differential interferometry.
I have successfully processed the the 3 tiff images per scene into SLCs using par_s1_SLC, so now I have 6 total SLCs.
I am having difficulty with the next few steps. According to the documentation, I should use SLC_cat_S1_TOPS. I am having difficulty conceptualizing what this step does, as it appears to combine all of my SLCs from the two separate acquisitions and output them into one SLC. I've made my 3 SLC tab files accordingly, and have tried using the tool, but receive a really non-descript error: "ERROR: cannot create output SLC-3 swath SLC"
Any insight into what my next steps are would be greatly appreciated. I am currently running the 20150702 version of Gamma. Let me know if there is any other useful information I can provide.
Thank you,
Kendall
Replies (4)
S1 TOPS-mode SLC data processing - Added by Charles Werner about 9 years ago
Hello Kendall,
A single Sentinel-1 frame has 3 subswaths, These 3 subswaths are treated as a
single frame, so you do not need SLC_cat_S1_TOPS. You only need that program if you
are concatenating multiple frames. Concatenation of frames again leads to 3
subswaths and the associated files and metadata. Follow the latest version of
the users guide that I sent today to you and is attached here, as well as the
latest script versions, also attached.
The SLC_tab contains the list of the SLC file, the SLC parameter file and a file
that describes the individual bursts called the TOPS_par. You can look at these
files with
any text editor. The SLC_tab serves as an input to the different programs to
specify an SLC multi-swath image. You do not need to have 3 subswaths in the
SLC_tab, you can
have 1, 2, or 3 subswaths. All SLC_tabs though have to have the same number of
subswaths.
Best regards,
Charles
| S1_poly_overlap (14.1 KB) S1_poly_overlap | |||
| S1_deramp_TOPS_slave (9.93 KB) S1_deramp_TOPS_slave | |||
| S1_coreg_overlap (36.4 KB) S1_coreg_overlap | |||
| S1_coreg_subswath_overlap (36 KB) S1_coreg_subswath_overlap | |||
| S1_deramp_TOPS_reference (3.03 KB) S1_deramp_TOPS_reference | |||
| S1_coreg_TOPS (23 KB) S1_coreg_TOPS | |||
| Sentinel-1_users_guide.pdf (2.92 MB) Sentinel-1_users_guide.pdf |
RE: S1 TOPS-mode SLC data processing - Added by Alessandro Novellino almost 8 years ago
Hi all,
I am facing a similar problem to Kendall,
Essentially I have read the Sentinel TOPS images with S1_TOPS_preproc but then I am a little bit confused because I am planning to selects 3/4 bursts of the full burst SLC and I have already done SLC_copy_S1_TOPS, however, after this step which path I should follow:
- run SLC_deramp_S1_TOPS, SLC_mosaic_S1_TOPS and coregister the files as other normal SLC, so by using rdc_trans?
- run directly S1_coreg_TOPS and then remove the azimuht spectral ramp with S1_deramp_TOPS_reference and S1_deramp_TOPS_slave?
Thanks in advance!
Alex
RE: S1 TOPS-mode SLC data processing - Added by Charles Werner almost 8 years ago
Hello,
The only reason to run SLC_deramp_S1_TOPS is to deramp the SLC when measuring
offsets. The oversampling of the SLC that is part of the offset estimation based
on image intensity requires this deramping. Otherwise, the interferograms and
running S1_coreg_TOPS is all done with original (ramped) data.
resampling of the SLC data is done using the ramped data. internal to the
resampling program, the data are deramped, then resampled and then reramped.
In your case I would select the 3 or 4 bursts you want from each SLC scene and
then just work with the smaller SLC.
Check the Sentinel-1 Users guide in the DIFF/html directory.
RE: S1 TOPS-mode SLC data processing - Added by Alessandro Novellino almost 8 years ago
Hi Charles,
Many thanks!
Alex