Coregistration with Back Geocoding does not work

ABraun · December 20, 2018, 8:40pm

every problem is worth trying again at a later time. Sometimes there are memory issues or data stuck in a stream.

volkan · March 6, 2019, 8:48pm

Hi,

I faced with this problem. As a solution, I restarted the PC and then opened extra space in C and D drives. It worked.

PS: SNAP 6

houda · March 19, 2019, 1:43pm

Hi Sumiya i’m having the same problem can you please help me !

ABraun · March 20, 2019, 12:58pm

please provide more information: What data are you using, what is the result of the BackGeocoding (empty file, error message…) and most importantly - have you already updated SNAP to the latest version using Help > Check for Updates

houda · April 19, 2019, 12:16pm

I have solved the problem by doing an update in SNAP but i have a problem with the final result I think it’s the bug with the Topo removal

ABraun · April 19, 2019, 1:11pm

maybe your study area is located ouside the SRTM area?

source: https://www2.jpl.nasa.gov/srtm/coverage.html

Did you select SRTM 1Sec in the topographic phase removal as well?

houda · April 19, 2019, 2:25pm

no i’m using STRM 3SEC i have a result like an DEM …and i’m using snap 6.0

ABraun · April 19, 2019, 2:40pm

one result is the topographic phase derived from the DEM (looks similar) the other is the remaining interferogram. The second is what you need for the subsequent steps.

houda · April 22, 2019, 2:03pm

as you can see my final result is like a DEM and the interferogram after removing the topo is not good it’s like it didn’t remove it at all and i think the bug with this step, please can you tell what to do ?

ABraun · April 22, 2019, 3:11pm

Perhaps you can slightly increase the quality of the product by multi looking to a lower spatial resolution (e.g. 20 meters) and Goldstein Phase Filtering.
But note that Sentinel-1 repeat pass interferometry is not the best data source for DEM generation. This has multiple reasons (temporal decorrelation, perpendicular baseline, wavelength) and atmospheric conditions can additionally reduced the quality.

houda · April 23, 2019, 10:51am

I think you didn’t understand me, the outpout of topo phase removal is not correct can you please develop what i have to check exactly

ABraun · April 24, 2019, 9:08am

What makes you think the output is not correct?

Nasimiyu · August 15, 2021, 7:21am

Hi ABraun , i am also having the same problem.
Step 1 : i did coregistration which took like the whole day for two images, is that normal? RGB results only show one image color.
Then afterward I did all the interferometry steps, am getting a purple color image.
Kindly assist.

ABraun · August 16, 2021, 2:14pm

a red RGB means that the coregistration failed. Please specify what data you are using and which steps you undertook.