Dear All colleagues,
I am new to Sentinel-1 and SAR Analysis. I need guidance to preprocess my data. I want to perform time-series analysis (pixel by pixel) using Sentinel-1 data in the Paddy Fields area (quite a large area). My project needs high temporal resolution, so I need to combine ascending and descending data. In my study area, there are 2 tracks for descending and 1 track for ascending.
Is it possible to combine them? Please provide pre-processing steps to do that if that is possible
If you terrain correct everything the output should be stackable.
Do I need to apply coregistration? I heard that ascending and descending images do not overlay perfectly
Wondering if you are going to work with GRD or SLCs? Stacking them all together only is kind of possible if you calibrate in gamma0 and use the radiometric terrain correction methods for which all dependencies with incident angles, topography are removed, so that the final backscatter (not phase) can be stacked.
From my understanding this can be done usually only over flat areas. Please @mengdahl correct me if I am wrong
However, if what you are talking about is to use InSAR and decompose both ascending and descending data to obtain vertical / horizontal displacement, this is a total different story that can be also done, but using totally different approach.
So,which is the approach you are planning to apply?
Try to find the relevant tutorials. Ascending and descending do not overlay and anyway terrain correction is required to put them in map geometry. If all goes well after that step they should be stackable either out-of-the-box or by applying a small shift.
The incidence angle may be different, which may be important if you are using change detection on the data