Geostatistical Analysis and Mitigation of Atmospheric Phase Screens in Ku-Band Terrestrial Radar Interferometry

Abstract

A geostatistical analysis of the atmospheric phase screen (APS) affecting Ku-Band terrestrial radar interferometric (TRI) observations of a fast-flowing alpine glacier is made assuming a separable spatio-temporal covariance structure. Such a structure facilitates the mitigation of APS: the atmospheric phase affecting individual interferograms can be extrapolated form a set of persistent scatterers (PS) using regression-Kriging. After removing this estimate the residual APS is only correlated in time; its effect on surface displacement estimation is mitigated with a generalized least squares (GLS) inversion employing an estimate of the temporal covariance of the APS. The applicability of a separable covariance structure and the performance of the APS correction method are assessed on a TRI timeseries of Bisgletscher, a glacier in the southwestern Swiss Alps.