Ground moving target detection method of BFSAR (Bistatic Forward-looking Synthetic Aperture Radar)

Abstract

The invention discloses a ground moving target detection method of a BFSAR, and aims at solving problems of ground moving targets under configuration of the BFSAR. The method comprises the steps thatS1) original echo signals of different channels are pre-filtered; S2) Keystone transformation is carried out on filtering results of the different channels in the S1; S3) ground still-life clutters are inhibited by time-division adaption; and S4) an improved Wigner-Ville distribution method is used to accumulate target energy coherently. A de-inclination pre-filter and Keystone transformation areused to inhibit Doppler fuzziness and correct migration of a distance unit, influence of migration of the Doppler unit is eliminated by time-division adaptive cancellation, and the ground still-life clutters are inhibited effectively; and the improved Wigner-Ville distribution method is used accumulate the target energy coherently, and the signal to clutter / noise ratio is improved.

Description

technical field [0001] The invention belongs to the technical field of radar, and in particular relates to a ground moving target detection technology of a bibase forward-looking SAR. Background technique [0002] Synthetic Aperture Radar (SAR) is an all-weather, all-weather modern high-resolution microwave remote sensing imaging radar, which uses the relative motion between the radar antenna and the target area to obtain high spatial resolution. Synthetic aperture radar has played an increasingly important role in the fields of terrain surveying and mapping, vegetation analysis, ocean and hydrological observation, environment and disaster monitoring, resource exploration, and detection of small changes in the earth's crust. [0003] Bistatic forward-looking SAR (BFSAR) is a new radar system, and the system's transmitting station and receiving station are placed on different platforms. With the development of radar synthetic aperture radar in recent years, BFSAR plays an in...

AI Technical Summary

Problems solved by technology

Although the single-channel SAR system has low hardware requirements and a relatively small amount of calculation, it requires that the echo energy of slow-moving targets is stronger than that of ground objects, which is difficult to meet in practical applications

Moreover, the ground clutter spectrum will broaden under the airborne platform, making it more difficult for a single-channel SAR system to detect moving targets imaged in the main lobe

Multi-channel methods mainly include phase center offset antenna (DPCA), along-track interferometry (ATI) and space-time adaptive (STAP) methods; for the STAP method, see the literature "Ender, J.H.G.:'Space-time processing for multichannel synthetic apertureradar' , Electronics and Communication Engineering Journal, 2002, 11, (1), pp.29-38" and Barbarossa, S., Farina, A.: 'Space-time-frequency processing of synthetic radar signals', IEEE Transactions on Aerospace and Electronic Systems, 1994, 30, (2), pp.341-258; although STAP suppresses the clutter energy in the radar echo to a certain extent and improves the SCNR, but in the BFSAR echo: distance migration leads to echo Energy is dispersed in multiple range units, Doppler spectrum broadening leads to Doppler ambiguity, and Doppler unit migration causes Doppler spectrum signals to occupy multiple range units; thus increasing the detection of BFSAR under the traditional STAP method Configure the difficulty of moving targets below

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