I need to find the deformation of my required area. I’ve done the following steps for processing Alos palsar data as suggested by ABraun:
1. Coregistration(1master, 4slaves)
2. Deskewing
Interferogram formation
Terrain Correction
Up to this no problem. But I cant make the StaMPS export for the rest processing.
Next I want to apply PSI, then unwrapped with SNAPHU, and finally apply SBAS to find the deformation.
Could please select DEM HGT 1Sec auto download,
And as I mentioned before four images are too low number for PSI technique, Also skip step 4. Terrain correction, it is not needed, Also there is no need to apply topographic phase removal two times, because you already have checked the box subtract topographic phase in the step of interfergram formation.
in previous post , a good training, have a look at it please.
What is mentioned after terrain correction, needs from you some reading, about the Interferometric techniques
Dear sir, Sorry to bother you again. And thank you very much for replying me. I’ve select DEM HGT 1Sec while interfergram making. If I do not terrian corrected the interferogram and just try to make StaMPS export, the following error is showing:
What should I do now? And the area I’ve chosen for finding interferogram, there are only 11 images with same frame and path. Will it be worked with 11images? If I take 11 images, should I make 1 master and 10 slaves for co-registration?
I’m really very sorry to bother you. I’m a beginner in this sector. I’ve read the previous post of you and ALOS PALSAR processing this post too. It will be very kind of you, if you help me.
No need to apologize, the goal of this GREAT STEP FORUM, form the first time it is initiated, is to support the researchers from around the world by ESA, and also the members of this STEP FORUM, try up their best to help each other… this is my understanding
The idea of the PSI, is to find a coherent point scatterer for long term, during the processing you’ll find that some pairs should be removed because of many related problems such as jump phases, or many others, that’s why one reason is to have many images as much as we can,
In your case if there are no more images than 11, never mind, you could try, by selecting one as master and the other 10 as slaves, the suitable master could be selected by applying InSAR overview, to check up which one of the 11 is the best master.
Also now I found a very good summary, it is done by our colleague @ABraun you could go through it
I’m so glad of your successful, the main solution of this error is @mdelgado he was the first provider of this solution. And I was the first finder of this error
Well, if I got actually the solution means that I got this error before.
Othewise I could not anticipate it. But yes, you were the first one with which I have shared my solution.
Anyway, I am glad to contribute with my little help.
This is not the best plot to infer …
try with ps_plot(‘v-d’,1) or ps_plot(‘v-do’,1) depending of your processing options and you will see the mean LOS deformation velocity plot, which is much more comprehensive.
Still, my first suggestion is to increase the dataset, as 10 is a bit too low for inferring anything, as you could be seeing seasonal effects and so on…only with larger dataset you are able to see a evolution of the phase in time.
then, you can try ps_plot(‘v-d’,1,‘ts’) to see any time series of a selected point (you select the point by doing click on the image which opens)
You can check the StaMPS manual to see options and more.
Good luck!
@ABraun sir,
Product can’t be altered as if I altered them, SNAP is showing me “1st product should be co-registered SLC product and 2nd product is the interferogram”.
Is it a problem that I’ve subset the images before co-registered as If I take the full image storage problem is occurred? Thats why I’ve subset the required area with same co-ordinate for all images. Then I co-register the images.
subsetting Sentinel-1 data has reportedly brought errors in some InSAR cases. Try to reduce the data size in the split operator to the smallest possible extent, but leave it at that.
Maybe you can subset after the coregistration. But you have to go sure that both products (stack and interferogram stack) have exactly the same extent.
If I take S-1A image, doesn’t it occur space problem in my machine? I’ve not tried yet. Actually the paper I’m following they use Alos-palsar data. So I tried with this. There are only 7 images for S-1A SLC in my area.