Residual Motion Error Correction with Backprojection Multisquint Algorithm for Airborne Synthetic Aperture Radar Interferometry

Pengfei Xie; Man Zhang; Lei Zhang; Guanyong Wang

doi:10.3390/s19102342

Residual Motion Error Correction with Backprojection Multisquint Algorithm for Airborne Synthetic Aperture Radar Interferometry

Sensors (Basel). 2019 May 21;19(10):2342. doi: 10.3390/s19102342.

Authors

Pengfei Xie¹, Man Zhang², Lei Zhang³, Guanyong Wang⁴

Affiliations

¹ National Laboratory of Radar Signal Processing, Xidian University, Xi'an 710071, China. PerfeiShieh@126.com.
² School of Computer Science and Technology, Xidian University, Xi'an 710071, China. mzhang@xidian.edu.cn.
³ School of Electronics and Communication Engineering, Sun Yat-Sen University, Guangzhou 510275, China. leizhang@xidian.edu.cn.
⁴ Beijing Institute of Radio Measurement, The Second Academy of China Aerospace Science and Industry Corporation (CASIC), Beijing 100854, China. gywang.sar@gmail.com.

Abstract

For airborne interferometric synthetic aperture radar (InSAR) data processing, it is essential to achieve precise motion compensation to obtain high-quality digital elevation models (DEMs). In this paper, a novel InSAR motion compensation method is developed, which combines the backprojection (BP) focusing and the multisquint (MSQ) technique. The algorithm is two-fold. For SAR image focusing, BP algorithm is applied to fully use the navigation information. Additionally, an explicit mathematical expression of residual motion error (RME) in the BP image is derived, which paves a way to integrating the MSQ algorithm in the azimuth spatial wavenumber domain for a refined RME correction. It is revealed that the proposed backprojection multisquint (BP-MSQ) algorithm exploits the motion error correction advantages of BP and MSQ simultaneously, which leads to significant improvements of InSAR image quality. Simulation and real data experiments are employed to illustrate the effectiveness of the proposed algorithm.

Keywords: backprojection (BP); interferometric synthetic aperture radar (InSAR); motion compensation (MoCo); multisquint (MSQ); residual motion error (RME).