SNAPHU Unwrapping

[Sharon]

Hi ABraun,

Actually, I will analysis slow-move landslide with PSInSAR method.
I found some interference information of settlements in mountain areas by DInSAR with sentinel images. So, I want to check the move motion by interferograms in different time. I’m not sure will it work or not, because we couldn’t get good interferogram in mountain areas with other C-band data. In addition to that, I also tried to process the co-seismic surface deformation and land subsidence by DInSAR method.

Could you tell me how to check the topographic phase removed correctly or not? If there exist some problem in this step, how to solve it?

I have followed the steps in “Sentinel-1 TOPSAR Interferometry” tutorial from ESA website. And I have tried many times with different SAR images and parameters, but I couldn’t find the key to solve this error …

Thank you very much!

[ABraun]

I don’t know actually. Have you applied orbit files.
Would be interesting if other image pairs produce similar patterns.

[Sharon]

Yes, I used S1 TOPS Coregistration as the first step.
I will try to find what happen. Thank you!

[sentinelgyb]

When i was doing SNAPHU Unwrapping for the full extent of SLC image, After it run 5 hours, it says out of memory in assembling tiles. Now i have no idea what should i do to go through this step.

[falahfakhri]

might be the RAM is matter here in this issue,

[sentinelgyb]

Thanks for your response. This is the problem I have met. Any suggestion to me?

Assembilng tiles problem in Uwrapping

It says out of memory When i was doing the step of Uwrapping for the full extent with Snaphu. Unwrapping tiles have been done. The problem occurred in assembling tiles. The snapshot was as follwing: The RAM of my computer is 128G. [image] Anyone have met the same question with me? What should i do to complete this step? Thanks

[susantojoy]

Hi subham I have the same problem can you share me how you fix that problem.

[swatishree]

sir,
I tried snaphu phase unwrapping in ubuntu linux 14.04 LTS. My system is having 8 gb ram (dual boot). I got an error.

When i run the command - snaphu -f snaphu.conf Phase_ifg_HH_23Dec20­09_26Dec2010.snaphu.img 4672 it gives an error saying-
snaphu v1.4.2 27 parameters input from file snaphu.conf (84 lines total) only one tile–disregarding multiprocessor option Logging run-time parameters to file snaphu.log>

## Segmentation fault (core dumped)

Please guide me through this.I am not using cygwin terminal.
Thanks

[Samar_Yousef]

Hi all,
I tried snaphu phase unwrapping of ALSOPALSAR data, but I faced this problem;
Logging run-time parameters to file snaphu.log
segmentation fault

Have anyone an idea?

[ABraun]

I once found this, I guess it is still valid:

Doris 9 – Segmentation fault: error in SNAPHU

An explanation is given here:

This is caused by ctime() function in src/snaphu_io.c file [1]. To solve this problem, edit this file, change “#include <sys/time.h>” into “#include <time.h>”, and then compile and install again [2].

[Samar_Yousef]

Thank you for your reply, but I tried this and faced the same problem

snaphu v1.4.2
27 parameters input from file snaphu.conf (84 lines total)
Logging run-time parameters to file snaphu.log
Segmentation fault

Can you clarify your solve more, please?

[ABraun]

as it is not my solution I cannot provide any help, sorry.

[Andreea]

Hi.

How I can obtain Digital Surface Model (DSM) from Sentinel-1 SAR data?

[ABraun]

please have a look at this topic:

The Order of DEM Creating Steps

I am trying to create a DEM over my AOI. After reading plenty of topics, I have obtained a pair of S1A and S1B data. The baseline is 143.48 which is the longest I could find. As I read, it should be between 150 and 300 and around 70% of the values in the coherence histogram should be above 0.4. This is the histogram of my recent and best attempt. [image] After applying the steps below; 1) S1 TOPS Coregistration 2) Creating Interferogram 3) Debursting 4) Goldenstein Phase Filtering 5) Mu…

[Andreea]

Thank you!

[Remote-Radar]

Hi
who can help my about this error in Unwrapping by SNAPHU ? -Unexpected or abnormal exit of child process 2594-

[Remote-Radar]

Hi
I am trying to use snaphu to unwrap my data, too. but the following appears after running
Unwrapping tile at row 4, column 7 (pid 2977)
Unwrapping tile at row 4, column 8 (pid 2978)
Unwrapping tile at row 4, column 9 (pid 2979)
Unwrapping tile at row 5, column 0 (pid 2980)
Unwrapping tile at row 5, column 1 (pid 2981)
Unwrapping tile at row 5, column 2 (pid 2982)
*** Error in `snaphu’: corrupted size vs. prev_size: 0x00005585095fd840 ***
Unexpected or abnormal exit of child process 2977
Abort
PL help me

[tangyin]

You should attempt to modify the correlation coefficient in the SNAPHU Import , and then run again.

[cyntiamee]

hi, i,ve been finished the process, as you can see from the picture, i got the color dimension in abs_phase, but i saw from the other posted some people got into length dimension unit (meter). so how can i get that unit dimension. moreover, does anyone here have information how to analysis for subsidence suppose.

i will pleasure to know the anwers
thnk you

[cyntiamee]

i resolved it
otherwise i have another question, why the elevation on the land has number minus (-200 till - 500)?
does it right?