title: Near-Space TOPSAR Large-Scene Full-Aperture Imaging Scheme Based on Two-Step Processing.
abstract: Free of the constraints of orbit mechanisms, weather conditions and minimum antenna area, synthetic aperture radar (SAR) equipped on near-space platform is more suitable for sustained large-scene imaging compared with the spaceborne and airborne counterparts. Terrain observation by progressive scans (TOPS), which is a novel wide-swath imaging mode and allows the beam of SAR to scan along the azimuth, can reduce the time of echo acquisition for large scene. Thus, near-space TOPS-mode SAR (NS-TOPSAR) provides a new opportunity for sustained large-scene imaging. An efficient full-aperture imaging scheme for NS-TOPSAR is proposed in this paper. In this scheme, firstly, two-step processing (TSP) is adopted to eliminate the Doppler aliasing of the echo. Then, the data is focused in two-dimensional frequency domain (FD) based on Stolt interpolation. Finally, a modified TSP (MTSP) is performed to remove the azimuth aliasing. Simulations are presented to demonstrate the validity of the proposed imaging scheme for near-space large-scene imaging application.
authors.affiliation: School of Electronic Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China. qh_zhang09@163.com.
authors.forename: Qianghui
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: School of Electronic Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China. junjie_wu@uestc.edu.cn.
authors.forename: Junjie
authors.initials: J
authors.lastname: Wu
authors.affiliation: School of Electronic Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China. lwc6@163.com.
authors.forename: Wenchao
authors.initials: W
authors.lastname: Li
authors.affiliation: School of Electronic Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China. yulinhuang@uestc.edu.cn.
authors.forename: Yulin
authors.initials: Y
authors.lastname: Huang
authors.affiliation: School of Electronic Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China. jyyang@uestc.edu.cn.
authors.forename: Jianyu
authors.initials: J
authors.lastname: Yang
authors.affiliation: School of Electronic Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China. yanghaiguang@uestc.edu.cn.
authors.forename: Haiguang
authors.initials: H
authors.lastname: Yang
keywords: SAR; TOPS; modified two-step processing; near-space SAR; sustained large-scene imaging; two-step processing