No coregistration, no interferogram, what is the problem?

Microwave Toolbox
#1

I am currently working on time series data of ERS 1/2, Envisat and Sentinel 1. I am working on glaciers so I need to use offset tracking and convert the phase to height and displacement. I have processed correctly and got desired results in case of ERS1/2 and Envisat data. The problem came when I used Sentinel 1 data. The co registered slave image is always a blank black image with no value. I thought the problem is with the datasets, I changed the products with different baselines but also same happened. Further I tried to use the tutorial to use the sample data.
This Link

I believe that there should not be any error for this data-sets, as the experiment is verified. Is there any problem with the version of SNAP, I am using 6.0. See the images, I used the same dataset as given in tutorial.

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#2

please update your SNAP installation:
grafik

#3

I tried but results are same. I tried both from Macbook and Windows.

#4

The granules for my study are as follows, I tried all.
Can you check what is the problem.

S1A_IW_SLC__1SDV_20181114T121338_20181114T121405_024584_02B2FA_EB02
S1A_IW_SLC__1SDV_20180412T121329_20180412T121356_021434_024E7E_3185

I have chosen small perpendicular baseline for converting phase to displacement.

#5

dear @ABraun,
i have the same problem.
it appears when the master follows the slave.
in my case the master is 20190220 and the slave 20190208. If i invert the pair all works.
i use the latest version of SNAP and all my plugins are upgraded on Ubuntu 18.04.
also @maxdragonheart has a similar problem.
You can try using :
S1A_IW_SLC__1SDV_20190208T165655_20190208T165723_025841_02E013_F08C
S1A_IW_SLC__1SDV_20190220T165655_20190220T165723_026016_02E64D_7066

let me know.
Ciao.

Apply Orbit File Error: No orbit file found
#6

is there a reason why you don’t work with the inverted pair then?

#7

Generally, I would recommend the SRTM 1Sec DEM in the BackGeocoding step (instead of the predefined 3Sec) and use the TOPS coregistration with ESD.

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#8

you might use one or the other, according to your needs and software must work always, without problems. in this case, i used these images only for tests.
indeed, if i use srtm1m back geocoding works, but doesn’t mask sea area.
There’s something wrong. In SNAP 6.0 beta version there aren’t problem.

#9

Thank you, it worked well. I tried SRTM 1sec DEM.

#10

A very low resolution DEM like GETASSE30 is perfectly fine for TOPS coregistration and saves download time. Going to higher resolution gives no benefit.

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externalDEMApplyEGM for Back-Geocoding?
#11

I agree, but it reportedly solved problems with the download of SRTM90 in several cases.
My point was that changing the DEM source can narrow down the problem.

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