Developped from CNES historical Diapason Chain, adaptated python modules and OTB filters and applications are now available for the OTB community under the remote module called DiapOTB.
OTB filters and applications can be used independently or chained via python module scripts.
Four interforemetric module scripts are proposed as examples :
- diapOTB.py and diapOTB_S1IW.py for interferometric image pairs,
- SAR_MultiSlc.py and SAR_MultiSlc_IW.py for interferometric multi temporal images
Images from Sentinel1 (Stripmap or IW mode) and Cosmo-Skymed (stripmap or spotlight modes) sensors are supported. In a near future, the processing of images from TerraSAR-X will be included. Other missions, particularly with open data access will also be considered.
These two illustrations show terrain displacements after the volcanic eruption of Taal Island (Philippines, South of Manilla) that occured on January 12th 2020, computed on CNES cluster with DiapOTB from a set of ascending and descending Sentinel-1 pair (resp 2020/01/11-17 for the south part of the Island and 2020/01/9-21 for the north part). One fringe represents a displacement of half the wavelength in Line Of Sight (LOS), that is about 2.8 cm for Sentinel1.
DinSAR technic uses Single Look Complex phase difference between two Radar images of the same area acquired under similar orbital conditions. DInSAR require a set of specific fonctions like precise deformation grid from correlation step to perfectly super impose the two images before computing the interferogram. Main tools for DinSAR processing are now available and open for user improvement inside the DiapOTB remote module for the community.