Use of Sentinel-1 SLC data in iota2
iota2 can use Sentinel-1 time series, but only GRD (ground range detected), which means that interferometric information can't be exploited. For some applications, having access to interferometric coherence may be useful and iota2 could exploit it for classification and regression tasks.
In order to derive interferometric information from a pair of SLC images, several processing steps have to be performed. The whole procedure can be complex (!) but fortunately, OTB has a remote module for that (https://gitlab.orfeo-toolbox.org/remote_modules/diapotb). DiapOTB can take a series of Sentinel-1 images and generate the interferometric products (amplitude, phase and coherence). The whole processing is performed in sensor geometry, and the final products can be ortho-rectified afterwards.
In iota2, we would need to build a pipeline which does the processing in memory and generates the products in the S2 tile reference system so that the standard iota2 pipeline can be fed with these data.
The goal would be to build, for each S2 tile of a pre-defined region, a time series of 6-day interferograms (that is the interferogram between each acquisition and the previous one in the same orbit). This can probably be done by adapting the following processing chain provided by DiapOTB:
https://gitlab.orfeo-toolbox.org/remote_modules/diapotb/-/blob/master/python_src/SAR_MultiSlc_IW.py
This issue needs feedback from potential users and from SAR experts.