The forthcoming generation of SENTINEL-1 SAR demands for high precision phase preserving processors, that would handle the relatively large fractional bandwidth and the extended squint angle span due to TOPSAR. At the same time, efficiency is a must to handle the data rate that comes out from the two polarimetric channels and to cope for fast delivery of products. In this work, we discuss high level requirement on phase noise from interferometric applications and we propose some tests to validate the phase preservation of focusing algorithms in different acquisition geometries
