Three-pass DInSAR error


#1

Hello,

I am using SNAP 6 preview 5 and I am trying to study landside with Three-pass DInSAR.
I had the Defo and the unwrapped Topo interferograms. However, I can’t go any further with the DInSAR process because I am getting this error (displayed in the figure) when choosing the Three-pass DInSAR product.

I noticed also that it is not possible to select an input source product for the Three-pass DInSAR.

Could you please help me with this process.
Thank you.


Three-pass DInSAR
#2

@cwong could you please have a look at this operator? It seems that the operator has some issues with the source products


#3

Try doing it in the Graph Builder and use a ProductSet-Reader.


#4

Indeed you can try to do it like @cwong has suggested.
So instead of the Read operator you can add product reader and add as source defo pair and topo pair

however it does not change the fact that there is something wrong with the operator itself @cwong


#5

Thank you for the answer @cwong .
I tried the Graph builder but as @mfitrzyk said, there is a problem with the operator. I get the following error “Three-passDnSAR null”. Is there another way to process the D-InSAR with SNAP?


#6

OK. Thanks. We will look into it.


#7

I would be really interested in a working example of this tool because I have never seen it applied by now.


#8

Actually, I have a question about the D-InSAR process in SNAP.
As I understood from the discussions about DEM generation, we should not do the topographic phase removal step in order to get the desired DEM as a result.
Does this means that the topographic phase removal module can be used as a method to process the D-InSAR with SNAP?
In this case we can use a pair of S1 images after the soil deformation and then apply the topographic phase removal.
Is this correct? Can this be used as an alternative to the Three-passDnSAR ?
Thank you


#9

Here’s a reference for the 3-pass DInSAR technique:

On the derivation of coseismic displacement fields using differential radar interferometry: The Landers earthquake

Howard A. Zebker, Paul A. Rosen, Richard M. Goldstein, Andrew Gabriel, and Charles L. Werner
Jet Propulsion Laboratory, California Institute of Technology, Pasadena


#10

Thanks for the reply :slight_smile:
In fact I am looking for a method to process the DInSAR in SNAP.


#11

I have not personally tried it and there might be issues with the operator. However, the technique needs three input SAR products as the name implies.


#12

Hi, chayma. I have met the problem as you.If you have sloved it ,could you tell me the solution