I’ve tried several different variations in the Create Stack tool. So far, the results all look pretty similar. I have also tried the suggested higher polynomial which did not seem to alter the results much.
Coregistration (in the warp tab, I use the bicubic interpolation method)
Interferogram Creation (I also check the box for removing the topographic phase and include coherence estimation in this step, I see some people advise this as a separate step)
Goldstein Phase filtering
SNAPHU export
SNAPHU Phase unwrapping (so far I have had success using only the DEFO method)
Hey i have been following these above mentioned steps for interferometry but I m getting error at snaphu export.I’m using ALOS 2 PALSAR2 data in snap 7.0.
Thank you
Hello sir, I have been trying for interferometry in snap software. As the steps mentioned above by the ballistic I have followed them. but I am getting an error when I perform phase unwrapping. The steps were coregistration, interferogram creation, phase filtering, and SNAPHU export. After this export, there were coherence and phase images, which were not opening in snap software. I am not sure where I have done the mistake. and the screenshots of the results ha been attached.
Thank youphtos.docx (3.9 MB)
as you are using a quad-pol product, i recommend to use the “select band” operator at the beginning and perform the workflow on HH first to test if everything works alright. The images you currently show include all polarizations, which does not make much sense at the beginning. Please check how phase quality can differ for the polarimetric bands: Effect of polarization on interferometric products
The SNAP workflow for polarimetry you described is working with single polarization images, so I recommend to repeat it with only one polarization at a time. Then your interferograms should look more typical (currently, you are displaying an RGB image of several bands).
Maybe also this tutorial helps you: Interferometry Tutorial with Radarsat-2 It was based on Radarsat-2 images, but the steps are the same for ALOS-2.
Hello Sir, I have been trying interferometry by using only one polarisation. I got stuck at the SNAPHU export step. When I export the image file of the unwrapped phase is missing. I am not getting what will be the reason for this. I have attached the screenshots of the processing steps. please provide me the solution for this error. Thank you.images interferometry.pdf (518.7 KB)
Hello,
I have been trying for snaphu unwrapping. Even after following the steps from the above pdf still it showing the error and phase unwrappin is a problem. I am not getting whther there is problem with the system im using or software. please suggest something so that i can try.
SNAPHU is very particular in that you HAVE to set up the inputs correctly. This can be a bit hard to follow at times if you have not been diligent in setting up how you write your new data.