Can you please check after which of these steps the image turned black?
sir after debursting im using polarimetric speckle after speckle its turning black .
Please try Polarimetric Matrix Conversion > C2 after deburst, then check if your data is still there and if so, then apply the Polarimetric Speckle Filter.
i have tried this but still turning black … but if i use H/a decompose after debursting and then atlast applying single product speckle filter on the output of H/a decomposition then its working . with polarimetric speckle filter its turning black
also sir i wanted to know if i am following the right approach my study area is comming in iw3 2to5 burst and iw2 2to5 burst . and i wanted to check the change in alpha value on 1st October and 25th October.
1st October image IW2 → split → orbit->calibrate->s1geocode-> debusrt
IW3-> split → orbit->calibrate->s1geocode-> debusrt then merging IW2 and IW3 and afterwards decomposing it and applying single product speckle filter.
25st October image IW2 → split → orbit->calibrate->s1geocode-> debusrt
IW3-> split → orbit->calibrate->s1geocode-> debusrt then merging IW2 and IW3 and afterwards decomposing it and applying single product speckle filter.
and then corregistring both 1st october and 25th october product and then geometric correction .
is this the right approach ???
Which operator is this? Doesn’t seem necessary at this step.
sir this is S1 back geocoding
hm, BackGeocoding requires two products actually.
Hard to understand what you mean.
Have you seen this? Sentinel-1 SLC Preprocessing Workflow for Polarimetric Applications: A Generic Practice for Generating Dual-pol Covariance Matrix Elements in SNAP S-1 Toolbox[v1] | Preprints
It considers multiple cases, including yours I guess.
sir actually my area comes in 2 subswath as i mentioned earlier i want to analyze the alpha angle values between date 1st oct and 25th oct . so for that i am using this approach . am i doing it right
1st October image IW2 → split → orbit->calibrate->s1geocode-> debusrt
IW3-> split → orbit->calibrate->s1geocode-> debusrt then merging IW2 and IW3 and afterwards decomposing it and applying single product speckle filter.
25st October image IW2 → split → orbit->calibrate->s1geocode-> debusrt
IW3-> split → orbit->calibrate->s1geocode-> debusrt then merging IW2 and IW3 and afterwards decomposing it and applying single product speckle filter.
and then corregistring both 1st october and 25th october product and then geometric correction .
is this the right approach ??
sorry, I still don’t get why you would apply BackGeocoding on a single-date sub-swath.
sorry sir i was just following that literature as he mentioned in it . i got your point sir
regards
vaibhav .
apart from S1 backgeocoding the process i am following to generate decomposition products is fine ?
sir my area of study lies in 2 subswaths IW2 and IW3 bursts (2to5). can anyone please tell how to start the processing . should i merge the subswath in one single image and then generate the interferogram and coherance map??? please help
I agree that the referenced literature is not very clear ragarding this case.
According to the Grahp Builder of SNAP, this is the suggested approach to calculate an interferogram (including coherence) from two sub-swaths:
The two Read operators use images of different dates and the TOPSAR Split select IW1 and IW2 accordingly. They are then coreistered by BackGeocoding, the inteferogram is computed and debursted and both parts are merged using TOPS Merge.
I think this hopefully makes it a bit clearer. You were probably right from the beginning already.
what about coherence sir i same after interferogram do we need to add coherance box also ?
secondly
in this graph we havent applied callibration where to add that
you can directly include coherence estimation in the interferogram module, so you don’t need two separate operators.
I’d say after TOPS Split the latest.
sir if i first merge two subswaths of same date like for example in my case if i merge the two subswath IW2 and IW3 of 1st october and same i do with 25th october image and afterwards i calculate inerferogram and coherance will it be right ?
According to the graph shown above, you should first coregister the sub-swaths with BackGeocoding, then calculate coherence and merge as a last step.
hello @ABraun
How to get Statistics information.
I was doing it through Analysis tool
but I
couldn’t find any statistics information
I got it now
Thank you