Clutter suppression method suitable for high pulse repetition frequency (HPRF) waveform airborne radar

Abstract

The invention discloses a clutter suppression method suitable for a high pulse repetition frequency (HPRF) waveform airborne radar. The clutter suppression method comprises the steps of utilizing remote echo data above an nth array element altitude line to evaluate a long-distance main-lobe clutter Q, and utilizing Q to design a matrix filter P so as to extract short range clutter; utilizing P to extract short range clutter in first distance unit data xln of an nth array element, and estimating a short range clutter covariance matrix to adopt an opposite angle loading sampling covariance inversion method to calculate a pitching filter we; utilizing we to suppress short range clutter in xln, and obtaining data Y not containing short range clutter after all the data are processed; performing conversion from a pulse domain to a Doppler domain; taking out data from the Doppler domain and estimating a clutter suppression filter wk; utilizing the filter to suppress remote clutter, processing all Doppler channel data, and outputting to-be-detected data to be used for follow-up radar monitoring processing. According to the clutter suppression method, clutter suppression is achieved in the presence of array errors, the short range clutter can be suppressed well, industrialized achievement is easy, and target detection performance of the airborne radar can be remarkably improved.

Description

technical field [0001] The invention belongs to the technical field of radar and relates to clutter suppression of airborne radar, in particular to a clutter suppression method suitable for high pulse repetition frequency (HPRF) waveform airborne radar, used for clutter suppression of planar array radar with HPRF waveform wave suppression. Background technique [0002] Space-time adaptive processing (STAP) technology can effectively detect targets in complex ground clutter environments. According to the RMB criterion, when the number of training samples satisfying the independent and identically distributed condition is twice the system degree of freedom, STAP technology can achieve better performance. However, for non-frontal array airborne radars, since the airborne flight direction is inconsistent with the axis of the radar antenna array, the clutter is no longer distributed in a straight line in the angular Doppler space, and changes with the distance , the clutter sup...

AI Technical Summary

Problems solved by technology

In the case of known radar system configuration parameters, compensation algorithms can be used to compensate the distance dependence of clutter caused by front configuration, including Doppler frequency shift algorithm and angle Doppler compensation algorithm, Doppler frequency shift algorithm It is to calculate the main clutter Doppler frequency of the unit to be detected and each reference unit according to the radar system parameters, and then shift a complex phase factor for each reference unit along the time domain direction, so that the Doppler frequency of the clutter spectrum of each reference unit after compensation The frequency center is the same as the Doppler frequency center of the unit to be detected; the angle Doppler compensation algorithm is a two-dimensional translation along the space domain and time domain, and moves the center of the clutter spectrum of the reference unit along the angle-Doppler direction to the clutter of the unit to be detected. The position of the spectral center, so that the angle-Doppler center of the main clutter of each reference unit coincides with the angle-Doppler center of the unit to be tested, but these compensation algorithms are only suitable for the case of no distance ambiguity, that is, the ideal situation, but in reality, airborne radar, especially non-positive side airborne radar, is not always in this ideal state, and the non-ideal state will bring errors to the actual detection of the radar.

[0004] In 2009, Meng Xiangdong proposed a static weight pitch filter cascaded two-dimensional space-time processing method in the Journal of Xidian. In the case of no error, this method can effectively suppress non-frontal array radar clutter, and make full use of the effective information from the planar array; however, the clutter suppression performance of this method is not ideal in the presence of errors

In actual situations, most of the airborne radars are in error situations, so the method of cascading two-dimensional space-time processing with static weight pitch filtering is not very applicable, especially it cannot effectively suppress short-range clutter, especially non- The positive-side airborne radar configuration will cause serious clutter non-uniformity, resulting in the mismatch between the adaptive filter estimated from these non-uniform samples and the clutter in the unit to be detected, which will degrade the clutter suppression performance and cause the radar system Therefore, for radars with non-frontal array configurations, there is an urgent need for a method that can effectively suppress clutter

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