Problem with ground control points

s1tbx
#1

Hi
I’m doing project about change detection using SNAP and Sentinel 1A SLC data. I have found instructions “Sentinel-1 TOPS Interferometry, Michael Foumelis” . I followed instructions step by step and everything works great, but at the end when I try to calculate statistics I have only one “layer” geometry, but in instructions there are two “layers” geometry and ground_control_points. Does anyone have experience with that instructions and maybe know how to solve that problem??

Another problem is that when I load .zip file in SNAP in band I have i,q and intenstiy for all 3 IW, but when I open ground_control_points table it si empty? When I load from that same data .tiff file from measurement than in bands I have band_1 and there are all ground control points, does anyone know what is the problem?

1.png1920×1080 956 KB
2.png1920×1080 916 KB

P.s. sorry if there is already topic about this, I try to find it but I coludn’t

#2

Initially with a S1 product there are no GCPs. If you open the tif bands directly then the tif reader inserts some GCPs it finds in the tif metadata but, the products are not intended to be opened this way.

#3

Thank you for answer :slight_smile:

Can you please describe me how to insert GCP?
I tried with GCP placing tool to pin some points on image Intensity IW3 but when when I do S1-TOPS Split on that image after that GCP which I added dissapear :open_mouth:

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