Surface Subsidence

how many patches did you select during mt_prep_snap?

Seems like the raster is excessively large…

From Mdelgado comment,

I replace the ps_load_initial_gamma.m file in Stamps4.2b/matalb.
Then stamps(2,2) step is running nicely.
Thank you.

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interesting - thank you for reporting. I thought this was no longer necessary.

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stamps(6,6)

STAMPS: ########################################
STAMPS: ####### StaMPS/MTI Version 4.0b6 #######
STAMPS: ####### Beta version, Jun 2018 #######
STAMPS: ########################################

STAMPS: Will process current directory only

STAMPS: ########################################
STAMPS: ################ Step 6 ################
STAMPS: ########################################
STAMPS: Directory is 6_psiexport

PS_UNWRAP: Starting
Phase-unwrapping…
GETPARM: small_baseline_flag=‘n’
GETPARM: unwrap_patch_phase=‘n’
GETPARM: scla_deramp=‘n’
GETPARM: subtr_tropo=‘n’
GETPARM: tropo_method=‘a_l’
GETPARM: drop_ifg_index=
GETPARM: unwrap_hold_good_values=‘n’
PS_UNWRAP: Code to hold good values skipped
GETPARM: unwrap_time_win=730
GETPARM: unwrap_method=‘3D’
GETPARM: unwrap_grid_size=200
GETPARM: unwrap_gold_n_win=32
GETPARM: unwrap_prefilter_flag=‘y’
GETPARM: unwrap_gold_alpha=0.8
GETPARM: unwrap_la_error_flag=‘y’
GETPARM: unwrap_spatial_cost_func_flag=‘n’
GETPARM: max_topo_err=20
GETPARM: lambda=0.0554658
PS_UNWRAP: n_trial_wraps=0.261384
Resampling phase to grid…
Number of interferograms : 50
Number of points per ifg : 269037
Number of resampled points: 7915
Interpolating grid…
Number of unique edges in grid: 18636
Unwrapping in time-space…
Estimating look angle error (elapsed time=199s)
Using sequential daisy chain of interferograms
Smoothing in time (elapsed time=201s)
Unwrapping in space…
Processing IFG 1 of 50
Error using fread
Invalid file identifier. Use fopen to generate a valid file identifier.

Error in uw_stat_costs (line 159)
ifguw=fread(fid,[ncol,inf],‘float’);

Error in uw_3d (line 163)
uw_stat_costs(options.unwrap_method,options.variance);

Error in ps_unwrap (line 235)
[ph_uw_some,msd_some]=uw_3d(ph_w(:,unwrap_ifg_index),ps.xy,day,ifgday_ix(unwrap_ifg_index,:),ps.bperp(unwrap_ifg_index),options);

Error in stamps (line 503)
ps_unwrap

Please tell me the solution for this error.

Thank you

After replacing the ps_load_initial_gamma.m file in matlab folder. It is working up to stamps (5,5) without any interruption.

After finishing, the stamps(5,5). i run this below command as shown in stamps manual.

ps_plot(‘w’)
Warning: MATLAB has disabled some advanced graphics rendering features by switching to software OpenGL. For
more information, click here.
Color Range: -3.14159 to 3.14159 rad

ans =

Figure (1: w) with properties:

  Number: 1
    Name: 'w'
   Color: [0.9400 0.9400 0.9400]
Position: [672 479 560 420]
   Units: 'pixels'

Show all properties

While running stamps(6,6) i’m getting above posted error.
please check it once.
Thank you.

this looks like the case here where triangle was installed but the path was not correct in the config file. After you source the config file in the shell, you should be able to get the tool parameters when you type “triangle”. Please test.

Thank you so much ABraun… Its working

good job - great you found the error source!
Could you please shortly tell what you changed so people which also face this error can learn from it?

I didn’t installed Snaphu in my ubuntu platform, after installation of snaphu, directly using below command
sudo apt install snaphu .
stamps (6,6) running smoothly in matlab.

Thank you so much ABraun once again.

very good, thank you

Dear ABraun,
I processed upto stamps(8,8) steps successfully. Then how can i create time series for this data set.

Thank you.

Please tell me the time series generation steps after stamps(8,8)

Thank you

Please check chapter 5 of this excercise: http://eoscience.esa.int/landtraining2017/files/materials/D4P1a1I.pdf

Or you try the StaMPS-Visualizer, SNAP-StaMPS Workflow (instructions here)

Thank you so much ABraun.

Dear ABraun,

I try to run interferogram in SNAP for Stamps export,
But while generating the interferogram formation for all images (50 SAR images). The output is just generating one brust only instead of 5 brusts.
I reprocessed once again but still I’m getting same output (small area) instead of large area of coverage.

It is running from last 14 hours, still it is not completed.

Please give me suggestion,

Thank you.

I don’t really understand the problem, sorry. Maybe you can first describe how you prepared your data until the step of interferogram formation.

Did you see that there is a python script which does this job for you? Snap2stamps package: a free tool to automate the SNAP-StaMPS Workflow
Also well documented here: https://gitlab.com/Rexthor/gis-blog/-/blob/master/StaMPS/2-3_snap2stamps.md

In SNAP

  1. Apply orbit file for all images (50 SAR images)
  2. Back geocoding
  3. Stack
  4. Debrust
  5. Subset
  6. Finally Interferogram Formation

But while generating the Interferogram it is not creating the total selected area, it just crating one small area.
My doubt is why it is not creating the selected area interferogram?

It is showing still running (from last 15 hours same output, size is not increasing).

Acutally, the first step should be TOPS Split.

maybe the area is not covered by both images? You can only get interferograms from areas which are covered by bursts of both dates.
Sometimes the bursts are shifted and refer to different areas. An example is given in this tutorial: Pages 3 and 8.
DEM generation with Sentinel-1 - Workflow and challenges

You can open all images (after Orbit file) in SNAP and test in the World View window if they cover the same extent.

Based on the volume of data, the processing time is not surprising to me.

Dear ABraun,
These are the steps i followed to generate the Snap2Stamps input.

In SNAP:

  1. First i created Topsar-split and orbit file as shown in the below figure, for all the SAR imgaes.


I selected IW3 only shown in below figure.


2.Selected master image, Using InSAR stack overview.

3.Back geocoding for all the images, Master(20180917) selected in first and then all the images.

4.Debrust

5.subset


6.Interferogram formation

Is it correct?

looks ok so far. Did you check if all bands in the coregistered stack contain valid data?