The DEM generated from Sentinal SLC data in about half in length with swath

s1tbx
#1

I am trying to produce the DEM out of the Sentinal SLC data. I am only able to generate DEM for the half of the area. Any suggestion?

S1A_IW_SLC__1SSV_20141026T124702_20141026T124729_003001_0036B0_6419_UNW_Orb_Stack_ifg_deb_flt_dem_TC_elevation_VV
S1A_IW_SLC__1SSV_20141026T124702_20141026T124729_003001_0036B0_6419_UNW_Orb_Stack_ifg_deb_flt_dem_TC_elevation_VV.jpg990×692 169 KB

#2

looks like the unwrapping failed at half process.

Could you please post screenshots of

  • coherence
  • the SRTM below (right-click > add elevation band)
  • interferogram
  • unwrapped interferogram
#3

C

S1A_IW_SLC__1SSV_20141026T124702_20141026T124729_003001_0036B0_6419_Orb_Stack_ifg_coh_IW2_VV_26Oct2014_07Nov2014
S1A_IW_SLC__1SSV_20141026T124702_20141026T124729_003001_0036B0_6419_Orb_Stack_ifg_coh_IW2_VV_26Oct2014_07Nov2014.jpg990×692 150 KB
oherence

#4

Then it is clear! You have only half image, so from here the error you mentioned.

You can try to do again the interferogram, verifying that both images cover the same area.
From the plot it seems that one of the options below occurred:

  1. the slave only covers part of the master
  2. your processing got some error due to potential memory issues

Please check

#5

Thanks! ABraun and mdelgado

#6

The slave image should cover complete master image? Than the base line will also be minimum ?

#7

Master and Slave should cover your AOI. Otherwise you would not be able to retrieve all the information that you want.
Only in the overlapped areas with medium-high coherence values you are able to retrieve topographical phase using InSAR.

#8

sometimes the bursts of both images are not identical because the scenes are shifted in along track direction.
Check carefully in the TOPS Split part that both burtst ranges match the same area.

1 Like
#9

My area of interest is not coming all three swaths of the data. But, when I process it for DEM , I can see half of the area is covered. I downloaded the data by taking similar area of interest in the portal any advice?

#10

And how to check is covering AOI?

#11

Well, I would check it at the moment of downloading the data to process.

You can easily check that in the http://scihub.copernicus.eu by searching using the BBOX, and later seeing the footprint of the data you want to download.

#12

While downloading the data I can see that AOI. But, when I visualize in SNAP. The AOI is little outside from sawths. I am using Alaska Satellite Facility portal to download the data.

#13

Well, I guess it is indiferent which provider you use to get the data, but more or less you get an idea whether your AOI is totally or partially covered. If your AOI does not fit in a single orbit, then you should probably think in process more than one orbit, or searching for the orbit that covers the maximum of your AOI.