基于GLONASS的双基合成孔径雷达的预处理算法研究

A Pre-processing Algorithm of GLONASS-BSAR

摘要:

本文提出了一种基于GLONASS的双基合成孔径雷达(GLONASS based Bistatic Synthetic Aperture Radar, GLONASS-BSAR)的预处理算法。GLONASS-BSAR雷达系统采用俄罗斯导航卫星GLONASS作为发射机,接收机可以放置在任意平台,比如卫星、飞机、汽车或者地面。该系统有着低廉的成本、较好的安全性以及多视角等技术优势,应用前景广阔。然而,由于该系统属于非合作式双基地雷达系统,发射机与接收机时间、频率以及相位上不同步,对雷达处理引入了严重的技术限制。才外,该雷达系统的发射机卫星属于中高轨道卫星,因此接收信号信噪比极低,大大增加了后续信号处理的难度。因此,本文拟研究GLONASS-BSAR的预处理算法,获取该雷达系统的同步。该预处理算法通过对接收到的信号进行时间延时、频率、相位历史信息提取,能够消除双基合成孔径雷达系统带来的时间不同步以及相位不同步。实验结果表明,该预处理算法能够消除接收信号的时间不同步和相位不同步,同时运算复杂度低。

Abstract:

This paper proposed a fast pre-processing algorithm of GLONASS based bistatic synthetic aperture radar. GLONASS-BSAR is a kind of bistatic SAR system that GLONASS is the transmitter, while the receiver can be mounted anywhere, such as satellite, aircraft, vehicle or even fixed on the ground. Such a system benefits from low cost, good safety and multi-perspective. However, as such a system is a non-cooperative bistatic radar system, where the time, frequency and phase terms are not correlated between transmitter and receiver. In addition, as the transmitter employed in such radar system is middle orbit satellite, the SNR of the received signal is extremely low, bring difficulty to subsequent signal processing. As such, the article deals with the pre-processing issue of GLONASS-BSAR, aimed at achieving synchronization of such radar system. By extracting time history, frequency history and phase history, the proposed algorithm removed the time offset and phase offset. The experiments demonstrate that such an algorithm is able to achieve signal correlation from accuracy perspective and low computational complexity.