Multi-channel two-pulse clutter cancellation method for bistatic forward-looking SAR based on nlcs imaging

Abstract

The invention discloses a bibase forward-looking SAR multi-channel two-pulse clutter cancellation method based on NLCS imaging. The method first uses the keystone transformation to correct the migration of the range unit, and then removes the azimuth space variation of the echo through the NLCS algorithm. , so that the clutter and the moving target are separated from each other in the two-dimensional space-time domain. Finally, according to the characteristics of the clutter echo, the clutter canceller is designed to suppress the clutter, thereby improving the signal-to-clutter ratio of the echo. It lays the foundation for the ability to detect moving targets.

Description

technical field [0001] The invention belongs to the technical field of radar, and in particular relates to a bistatic forward-looking SAR multi-channel two-pulse clutter cancellation method based on NLCS (nonlinear chirp scaling, nonlinear CS algorithm) imaging. 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 is a new radar system. By using the separation of transceivers to overcome the problem of forward-looking imaging blind spots in single-...

AI Technical Summary

Problems solved by technology

However, due to the serious range non-stationarity of bistatic forward-looking SAR, the estimation of the clutter covariance matrix is ​​inaccurate, and a large number of independent and identically distributed range samples are difficult to satisfy in practical situations.

As a result, the clutter suppression effect of the STAP method is not good

At the same time, because the radar transmitter and receiver are separated from different platforms, the traditional DPCA processing condition is difficult to meet, that is, after an appropriate time interval, the previous receiving phase center and the subsequent receiving phase center coincide

This limits the scope of application of DPCA

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