Comments on “Study of Systematic Bias in Measuring Surface Deformation With SAR Interferometry”

In a recent publication, Ansari et al. (2021) claimed (see, in particular, the Discussion and Recommendation Section their article) that advanced differential SAR interferometry (InSAR) algorithms for surface deformation retrieval, based on small baseline approach, are affected by systematic biases generated InSAR products. Therefore, to avoid such biases, they recommended strategy primarily focused excluding “the short temporal interferograms using long baselines decrease overall phase errors.” among various techniques, identified solution presented Manunta (2019) as processing approach where presence of above-mentioned (referred fading signal) compromises accuracy retrieved We show claim is not correct (at least) what concerns mentioned discussed (2019). Sentinel-1 dataset relevant same area Sicily (southern Italy) investigated (2021), we demonstrate products do any significant bias.