A Fourier-Based Image Formation Algorithm for Geo-Stationary GNSS-Based Bistatic Forward-Looking Synthetic Aperture Radar

• Published in: Sensors (Basel, Switzerland) Vol. 19; no. 9; p. 1965
• Main Authors: Zeng, Zhangfan, Shi, Zhiming, Xing, Sainan, Pan, Yongcai
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 26.04.2019; MDPI
• Subjects: Aircraft; Algorithms; Battlefields; Computer simulation; Data processing; forward looking SAR; Geometry; GNSS; image formation; International conferences; Military applications; Military technology; Radar equipment; Remote sensing; Signal processing; Spatial resolution; Synthetic aperture radar; Systems stability; Transmitters; China; forward looking SAR; GNSS; image formation
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s19091965

A Geo-Stationary GNSS-based Bistatic Forward-Looking Synthetic Aperture Radar (GeoSta-GNSS-BFLSAR) system is a particular kind of passive bistatic SAR system. In this system, a geo-stationary GNSS is used as the transmitter, while the receiver is deployed on a moving aircraft, which travels towards a target in a straight line. It is expected that such a radar system has potential for self-landing, self-navigation and battlefield information acquisition applications, etc. Up to now, little information from a research perspective can be found about GeoSta-GNSS-BFLSAR systems. To address this information gap, this paper proposes a preliminary image formation algorithm for GeoSta-GNSS-BFLSAR. The full details of the mathematical derivation are given. It is highlighted that, to overcome the long dwell time and spatial variance of GeoSta-GNSS-BFLSAR, a modified migration correction factor must be designed. In addition, the system performances and technical limitations of GeoSta-GNSS-BFLSAR such as focusing depth and spatial resolution are analytically discussed. In the end, a set of simulations including the image formation algorithm, focusing depth and spatial resolution were conducted for verification. It is demonstrated that the focusing performances of the proposed algorithm have a high level of similarity with the theoretical counterparts. This article thus proves the feasibility of GeoSta-GNSS-BFLSAR systems from a simulation level and establishes a foundation for the real applications of such a radar scheme in the future.