Error using uw_grid_wrapped (line 84) in StaMPS

Hello there,

I got an error at Step6 phase unwrapping using the StaMPS PSI method.

Error using uw_grid_wrapped (line 84)
Minimum dimension of the resampled grid (14 pixels) is less than prefilter window size (32)
Error in uw_3d (line 155)
Error in ps_unwrap (line 235)
Error in stamps (line 504)

Following the solution provided in the forum, I got the rslc file from the dim file in the SNAP. The dim file was obtained after co-registration and interferogram generation. Then I replaced the original file in the Geo folder and reran the mt_prep_snap and stamps(6,6). The error is still there.

1.Using Band Maths I created lat and lon bands in the stack_deb_subset product
2. Using File>Export> I exported the product in Gamma format
3. I now have lat.rslc and lon.rslc files (among other .rslc files for the other bands in the product)
4. Renamed lat.rslc and lon.rslc files to .lat and .lon (ex
5. Replaced the original and 20170704.lon files in the geo folder with these new files.
6. re-ran mt_prep_gamma (updated version)
7. re-ran Stamps(6,6)

I changed into a larger AOI. And rerun the steps in Snap2StaMPS. Finally, this fixed the error.

1 Like

thank you for sharing your solution, I’m glad you found one.

It is also possible to set the window size of the Goldstein Phase Filter to a smaller number with setparm(‘unwrap_gold_n_win’, 16) (or even smaller) in Matlab before running the step with stamps(6,6). This might solve the issue, but I am not sure to which extent it will influence the quality of the results, given that a small window is used.