Persistent Scatterers steps and interferograms generation
Tagged: persistent scatterers
February 5, 2015 at 11:53 am #697
While waiting for more documentation to come,
I open a new topic on this matter for the newcomers.
In Sarproz, Persistent Scatterers interferometry is applied to un-filtered full-resolution data.
This means that you do not need to generate interferograms if you want to process Persistent Scatterers.
It is suggested to process interferograms if you want to carry out weighted multi-temporal approaches (like quasi-PS).
In such case, before processing the interferograms, you have to choose from the “dataset selection” window the images graph that you want to process.
For classical PSI, these are the steps to follow (as mentioned in the notes by Timo http://www.sarproz.com/by-timo-balz/)
– preliminary analysis (section 1.4.1 of the manual)
– preliminary geocoding (1.4.2)
– phase2height and phase2flat constants generation (220.127.116.11 and 18.104.22.168)
– APS estimation (22.214.171.124)
– Sparse Points processing (126.96.36.199)
December 26, 2018 at 1:50 am #3634
I want to apply PSInSAR with these steps. But I have some questions.
phase2height and phase2flat constants generation (188.8.131.52 and 184.108.40.206) are not generated manually according to the following link. In which step it is done by automatically?
This entry posted at earlier 2015 and many updates have come to Sarproz up to the present. So, for the last version of Sarproz, could we sort the steps as follow:
– preliminary analysis (section 220.127.116.11 – 18.104.22.168)
– preliminary geocoding (22.214.171.124 – 126.96.36.199 – 188.8.131.52 – 184.108.40.206 – 220.127.116.11)
– APS estimation (18.104.22.168)
– Sparse Points processing (22.214.171.124)
December 26, 2018 at 2:14 am #3636
phase2height and phase2flat constants are automatically generated when needed.
if you check the log, you will find it written.
126.96.36.199 is coregistration refinement and you should NOT run it in normal conditions https://sarproz.com/manual/coreg_refine.html
APS estimation (188.8.131.52) + Sparse Points processing (184.108.40.206) is the standard approach.
However, is some cases it could not work (e.g. when the movement exceeds the unwrapping condition).
In such cases, you could stop at the APS processing. Or you could use the optional Graph Analysis and refinement module (220.127.116.11) https://sarproz.com/manual/graph_refinement.html
For data import and preliminary analysis, there are multiple tutorials here (they are in chronological order) https://www.sarproz.com/tutorials/
To start with InSAR time series, follow this tutorial: https://www.sarproz.com/publish/QYTutorial4.pdf
December 27, 2018 at 5:42 am #3647
Thank you for the detailed answer. I applied as follows;
– Preliminary Analysis (18.104.22.168 Reflectivity Map – 22.214.171.124 Mask Generation),
– Preliminary Geocoding (126.96.36.199 GCP Selection – 188.8.131.52 Ext. DEM in SAR Coordinates),
– Multi-Image InSAR Processing (184.108.40.206 APS estimation – 220.127.116.11 Sparse Points Processing)
and after these steps, I used load mask, scatter plots and time series module to visualization.
I have some questions at this point. There are several PSI algorithms like QPS, SBAS, StamPS and Squeesar. And incredibly Sarproz is capable of do all these methods. Are these steps belongs to which PSI method?
If I want to apply QPS to my study area, my roadmap should be how?
- This reply was modified 3 months, 3 weeks ago by volkan. Reason: link edit
January 6, 2019 at 1:42 am #3691
It looks like somehow my previous answer to this post went lost…
In your recap you list 3 main steps.
The first 2 are common to all Time-Series approaches.
The third one corresponds to the classic Persistent Scatterers method.
If you want to apply other methods, you might need to process interferograms first.
Also, in some cases you do not use the Sparse Points Processing module, but you might use the Graph Analysis and Refinement module.
We do not provide a roadmap for all these alternatives, because you have many options depending on your case (sensor, number of images, analyzed area, type of movement and so on).
However, we are collecting processing cases that we sometimes share (many of them cannot be published because data are sensitive).
You can find more hints here:
March 6, 2019 at 7:59 am #3889
I am trying to process 32 Sentinel SAR images and to use PS-Interferometry on it. The area that I want to process is a small area (about 1km2) and I would like to know if I am following the correct procedure. These are the steps that I have followed after having loaded and co-registered my data:
– In the Site Processing panel I perform the Preliminary Analysis (Reflectivity Map + Mask Generation) and the Preliminary Geocoding (GCP Selection + Ext. DEM in SAR Coordinates);
– In the Small Area processing panel I select the Area of Interest using the Grab option and then I apply in order the Sparse Points Selection, the Multi_image InSAR analysis and the Geocoding.
Am I missing any steps or doing anything wrong?
Many thanks for you help and best regards
March 6, 2019 at 2:37 pm #3890
nothing is wrong. yours is the simplest and most straightforward approach for analyzing a small area.
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