Use of SNAP for sentinel 1A


#21

Hi, yes if you follow the steps described in Section 5 of the S-1 Radiometric Calibration document, https://sentinel.esa.int/documents/247904/685163/S1-Radiometric-Calibration-V1.0.pdf, then your point targets could be used to match the LUT’s values.

However, I suggest you use a different approach - calculate the measured radar cross-section of your point targets (I assume these corner reflectors) and compare with the theoretical radar cross-section of your CRs. Ideally the differences should be small.


#22

thank you

how to find in which subswath of SLC IW image, does our location falls since subswaths when displayed using snap tool shows same lat long for each subswath
I need guidnace to merge 3 subswaths into single SLC image


#23

The TOPSAR-Merge module enables you to do that. The images just need to be first debursted (TOPSAR-Deburst).


#24

It’s not a perfect solution, but you can open the kmz file stored with each product in Google Earth and compare visually


#25

thank you
Mr. Peter
I tried hard to locate corner reflector in SLC , IW image of Sentinel 1A
Mr. peter, could you assist me to locate corner reflector ( trihedral triangular , 1m) in SLC image
deployment location: lat 12°38’15"N long 77°26’25.72"E
Dates of deployment: 21/07/2017, 2/8/2017, 7/9/2017, 25/10/2017, 18/11/2017, 6/3/2018


#26

Hi, I have obtained one of your image - from 06/03/2018 - and located your corner reflector. It is at pixel coordinates 10177, 12657 in sub-swath IW2. The cross in the image below shows the predicted position using a terrain height of 660 m. The CR will be at a similar position for your other images.


#27

Mr Peter, thank you, this will be quite helpful to me