My goal is to calculate fringes based on interferogram achieved.
I want to see landslide movement in that part (Central of Aceh District). Based on ground data. there are a lot of landslide in October 2015.
did you have good coherence between the images? Maybe you can post a screenshot of the coherence raster and its histogram.
Which snaphu method did you allpy? TOPO, DEFO or SMOOTH?
You could also consider making additional interferograms based on other image pairs, before and afterh October, just to get an impression on the general information which can be retrieved from the data.
theoretically, only the white areas in your coherence image reveal usable information. Then there are still atmospheric disturbances left which could affect your fringes. Try to apply a coherence mask on your interferogram as described below to see if the areas of interest are within that areas.
If the areas of interest are excluded by this mask, you need better coherence. You can achieve that by using an image pair with smaller temporal baseline (6/12 days are currently the smallest for Sentinel-1). You can also try to apply a better co-registration in order to improve the image alignment.
I got 5.52 day times differences but perpendicular baseline is -1169553 meter. Is it ok to proceed ?
yes, same polarization but not same IW number can not proceed Dr Braun, is is right?
one more thing,
low coherence will affect interferogram. a lot of site in Indonesia, especially in Aceh Tengah, low coherence is presented due to high vegetation. It means I have to elliminate result of DinSAR and can not use Sentinel data to produce a good interferogram due to atmospheric disturbance.
I read some papers. It is low coherence present but at least unwrapping phase can be proceed to D-InSAR with other sensor such as ALOS.
Sorry out of topic, I should move to another topic, but don’t do where to put. just go through my question and answer
every SLC product consists of 3 sub-swaths (IWs)
If your images are taken within the same track (which means they geographically align and have the same extents) there should be no technical problem using them for interferometry.
You can use the TOPSAR Split module to select only one of the three sub-swaths to decrease the file size.
About coherence: It is generally destroyed by vegetation cover. But if you use long wavelengths (ALOS PALSAR) you have higher chances to penetrate some of the smaller vegetation and get coherence from the surfaces. This however ends at high canopies.
I am a new user of SNAP, according to the tutorial you given above, the smooth installation of cygwin and SNAPHU, but when I put the contents of the red box on the contents of the paste -ENTER, there is a problem shown on the picture,I did not get the desired result，and I do not know why, Hope to get your answer, thank you very much!