US 6,549,160 B2 · Method of correcting azimuthal position of moving targets in SAR-images

Abstract

The positions of moving targets in the azimuthal direction which result from the SAR processing are falsified by components of the vehicle movement in the Doppler spectrum of the received signal, so that without the implementation of additional signal processing, moving targets are imaged in the SAR image at a false azimuth position. A method of repositioning moving targets in SAR images which consist of multi-channel range/Doppler measurement data X with NND Doppler resolution cells, defines on the basis of the filtering coefficients of the STAP transformed into the frequency domain, a family of NDZ pattern functions M, and determines testing functions T assigned to the measurement data. The true azimuth position of a moving target is then computed on the basis of the position of the maximum of the correlation between the testing functions and the pattern functions.

Claims20

Dependent claims

A method for repositioning moving targets in SAR-images comprising multi-channel range/Doppler measurement data X, with NDZ Doppler resolution cells, said method comprising:

defining a family of NDZ pattern functions M, based on filtering coefficients α and β for Space-Time Adaptive Processing, transformed into the frequency domain;
defining a testing function, based on the filtering coefficients α and β transformed into the frequency domain and on the multi-channel range/Doppler measurement data;
generating a correlation function K by correlating the testing function T with a selected function of the family of pattern functions M;
and
computing a true azimuth position of a moving target based on the position of a maximum of the correlation function K.

2 more elements

Apparatus for correcting azimuthal position of moving objects in a synthetic aperture radar image comprising multi-channel range/Doppler measurement data X with NDZ Doppler resolution cells, said apparatus comprising:

a data processor unit programmed to process said measurement data, according to the following steps
defining a family of NDZ pattern functions M, based on filtering coefficients α and β for Space-Time Adaptive Processing, transformed into the frequency domain;
defining a testing function, based on the filtering coefficients α and β transformed into the frequency domain and on the multi-channel range/Doppler measurement data;
generating a correlation function K by correlating the testing function T with a selected function of the family of pattern functions M;
and
computing a true azimuth position of a moving target based on the position of a maximum of the correlation function K.

3 more elements

A computer readable medium encoded with a computer program for correcting azimuthal position of moving objects in a synthetic aperture radar image comprising multi-channel range/Doppler measurement data X with NDZ Doppler resolution cells, by:

defining a family of NDZ pattern functions M, based on filtering coefficients α and β for Space-Time Adaptive Processing, transformed into the frequency domain;
defining a testing function based on the filtering coefficients α and β transformed into the frequency domain and on the multi-channel range/Doppler measurement data;
generating a correlation function K by correlating the testing function T with a selected function of the family of pattern functions M;
and
computing a true azimuth position of a moving target based on the position of a maximum of the correlation function K.

2 more elements

Dependencies are inferred from the claim text.

Method of correcting azimuthal position of moving targets in SAR-images

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Method of correcting azimuthal position of moving targets in SAR-images

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Abstract

Claims20