Retrieval of Three-Dimensional Surface Deformation Using an Improved Differential SAR Tomography System

• Main Authors: Zhigui Wang, Mei Liu, Kunfeng Lv
• Format: Article
• Language: English
• Published: MDPI AG 2019-02-01
• Series: Electronics
• Subjects: synthetic aperture radar; differential SAR tomography; squinted SAR; 3-D deformation; 2-D PPS
• Online Access: https://www.mdpi.com/2079-9292/8/2/174

Conventional differential synthetic aperture radar tomography (D-TomoSAR) can only capture the scatterers’ one-dimensional (1-D) deformation information along the line of sight (LOS) of the synthetic aperture radar (SAR), which means that it cannot retrieve the three-dimensional (3-D) movements of the ground surface. To retrieve the 3-D deformation displacements, several methods have been proposed; the performance is limited due to the insufficient sensitivity for retrieving the North-South motion component. In this paper, an improved D-TomoSAR model is established by introducing the scatterers’ 3-D deformation parameters in slant range, azimuth, and elevation directions into the traditional D-TomoSAR model. The improved D-TomoSAR can be regarded as a multi-component two-dimensional (2-D) polynomial phase signal (PPS). Then, an effective algorithm is proposed to retrieve the 3-D deformation parameters of the ground surface by the 2-D product high-order ambiguity function (PHAF) with the relax (RELAX) algorithm. The estimation performance is investigated and compared with the traditional algorithm. Simulations and experimental results with semi-real data verify the effectiveness of the proposed signal model and algorithm.