A Multi-channel Wiener Filter Method of Deformation Measurement for Simultaneous Multi-Angle Spaceborne D-InSAR

Abstract

Simultaneous multi-angle spaceborne synthetic aperture radar (SAR) can provide spatially diverse SAR images of the same scene without time lags. Through Differential SAR interferometry (D-InSAR), the system can extract accurate multi-dimensional deformations from the mixing differential tropospheric delay (DTD), which generally distorts deformation signals in single interferograms. This paper focuses on the multi-dimensional deformation estimation by simultaneous multi-angle spaceborne D-InSAR. A multi-channel Wiener filter (MWF)-based multi-dimensional deformation and DTD joint estimation method is proposed in this paper, which achieves the optimal estimation accuracy and reduces the loss of scene details. It was validated by both the simulations based on the system parameters of the future European Space Agency (ESA) Harmony mission and with real TanDEM-X bidirectional (BiDi) SAR data acquired over two scenes in California, USA. We analyzed the performance of the method in the presence of multiple error sources and investigated the impact of different observation geometries on estimation performance. The results not only demonstrate the potential of simultaneous multi-angle spaceborne D-InSAR in multi-dimensional deformation measurement, but also show that the proposed method can achieve good performance in terms of estimation accuracy and preservation of spatial resolution.