Java error in time of DEM generation

I have unwrapped the image and got the unwrapped image file. but cant able to understand how to add generic binary for this unwrapped file? and what should be the input for DEM generation? because when i try to generate DEM using this unwrapped phase image then the java.lang.nullpointer exception error comes can i solve those problem?please help me.

I think you don’t need to add anything because the SNAP downloads the DEM automatically, in a sense of using external DEM is needless, also the phase unwrapping that is mean you are already in the last step. I’d like to recommend clarify your steps and the goal of your processing, is it DEM generation or deformation map? in this case we could discuss step by step and find out the error in your processing.

step which i used is as follows

  1. TOPOS Coregistration
  2. Interferogram Formation
  3. Goldstain Filtering
  4. snaphu export
  5. snaphu import.
    now i try to generate DEM not deformation map. i want to generate DEM of an almost flat area.

in the manual its written as add the metadata for unwrapped phase image. how can i add this using SNAP?please help me out for generate a good DEM for my area.

Dear I’d like to recommend with the following steps,

TOPS COR ----> S-1 Ra. shift -------> S-1 AZ. shift ------> Deburst-------> Interferogram formation--------> subset (if you want to do!) ----------> Topographic removal-------->Malti looking-------->Filtering Goldstein------>Unwrapping

thank you sir. after unwrapping how can i add meta data and generate dem as discussed in the manual.

after unwrapping you are now in the step of SNAPHU importing ------->open the *.hdr file and then do the step of snaphu importing later on convert the phase to height.

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after snaphu import process may i run phase to height conversion for DEM generation?? and i want to open it through Arcgis or ERDAS. may i save it as geotiff product? please help me.

yes you could now go through this process interferometric ------>products-------->phase to height,

you could export your result as kmz file and open it via Google earth, also check out the other File----> Exprot----------> for instance GeoTIFF, ENVI, …Et cetera

sir, after snaphu export process i got the snaphu.conf file.i extract the file. and when i go for importing what should be the correct input for it? in wrapped phase tab if i insert filter interferogram phase product it shows it already contain a band name"i_ifg_srp" and when i insert the export derived phase product and unwrapped product it shows “snaphuimportop requires at least one product with insar metadata”. so i cant able to understand what should be the proper input for snaphu import option.

you should now run the snaphu under linux to get the unwrapped phase

if you did this step already, so now you need to open the *.hdr file

yes i have already run snaphu under linux .now i want to know what will be the next step?

i cant able to understand that what should be the proper input for import operation.

next step is to Open the *.hdr file in SNAP and run, Interferometric--------->unwrapping------>Snaphu Import-------> 1-read is the unwrapped phase and the 2-read is the *.hdr file,

when i put the phase product got from snapu export and input this .hdr file it shows snaphuimportop requires at least one product with insar metadata

Dear nothing you need to add from unwrapped product except of the *.hdr file, the other file is the same file which is already opened in SNAP, THE one you exported it,

when i give the filter interferofram product in the read wrap image tab then its shown its already has i_ifg_srd it ok or an error?