Subset operation shifts pixels

Microwave Toolbox
#1

We found that applying the subset operation sometimes produces results that don’t perfectly align with the full image. As someone pointed out, "The subset has an upper left coordinate that is exactly a multiple of 10 meters from the original image, however, the subselect region is some arbitrary rectangular area (i.e. not aligned with the pixel grid). Somehow, the SNAP subset step resamples to the nearest whole pixel, which causes the difference. "

Earth Engine link showing the diff:
https://code.earthengine.google.com/7e7caf9d3d42f6d0572993ccb59c42d3

#2

Thank you for your reporting. Is your case related to the use of gpt?

We had two similar issues lately:

#3

I used an XML graph file, not gpt, but I imagine they do the same thing. I can share the XML file and the product id if it helps.

#4

Can you share it if it works? Thank you very much. :kissing_closed_eyes:

#5

interesting, all reported issues are related to executing a graph.

I added this example to the official ticket: https://senbox.atlassian.net/projects/SITBX/issues/SITBX-780

1 Like
#6

See attached XML file that reproduces the problem (change the path from /data/s1 to wherever S1A_IW_GRDH_1SDV_20200427T092438_20200427T092503_032311_03BD30_2747.zip is saved)

external_vv.xml (7.1 KB)