SAR and reprojected coordinates

snap
#1

Good morning everyone!
I’ve produced an interferogram using snap and unwrapped it with snaphu. After reprojection in geographic coordinates (Range doppler terrain correction) I’ve noticed some discrepancies with the coordinates values.!
My question is: when I open a SAR image some Lat Lon coordinates are visualized in the bottom bar. Are these the true geographic coordinates corresponding to the pixels?

STEP1
STEP11623×959 359 KB

When I reproject the image and check it seems that the same point has different values in the reprojected map (they agree with google earth coordinates) and in the SAR one.
For example in the following image the same point (or cluster) has differet Lat value changing more than 1’.

step2
step21600×748 81.9 KB

Thank you for your help!
Cheers

#2

the lat/lon coordinates are not exact before terrain correction. They are estimated based on the image’s extent but it is still quite common that the location of single pixels changes after RD terrain correction.

#3

Ok, thank you @ABraun for your quick and kind reply!! :slight_smile:
Cheers
Vileda