Range-dependent clutter suppression approach for non-side-looking airborne radar based on orthogonal waveforms

• Published in: IET radar, sonar & navigation Vol. 9; no. 2; pp. 210 - 220
• Main Authors: Wen, Cai, Wang, Tong, Wu, Jian-xin
• Format: Journal Article
• Language: English
• Published: The Institution of Engineering and Technology 01.02.2015
• Subjects: Airborne radar; Algorithms; array signal processing; azimuth‐Doppler space‐time adaptive processing; azimuth‐Doppler STAP methods; Beamforming; cascaded algorithm; Clutter; Doppler shift; Elevation; high pulse repetition frequency; HPRF; interference suppression; Mathematical models; Navigation; nonside‐looking airborne radar; NSLAR; orthogonal‐waveform‐based elevation adaptive beamforming method; radar clutter; radar signal processing; range independency; range‐dependent near‐range clutter suppression approach; secondary data selection strategy; Sonar; space‐time adaptive processing; nonside-looking airborne radar; interference suppression; high pulse repetition frequency; azimuth-Doppler STAP methods; space-time adaptive processing; range-dependent near-range clutter suppression approach; orthogonal-waveform-based elevation adaptive beamforming method; range independency; NSLAR; azimuth-Doppler space-time adaptive processing; radar signal processing; Doppler shift; radar clutter; cascaded algorithm; secondary data selection strategy; HPRF; airborne radar; array signal processing
• ISSN: 1751-8784; 1751-8792; 1751-8792
• DOI: 10.1049/iet-rsn.2014.0018

Clutter suppression is a challenging problem in non-side-looking airborne radar (NSLAR) because of the range-dependent clutter. It is more intractable when the NSLAR operates at high pulse repetition frequency (HPRF). In this study, a cascaded algorithm is presented to realise clutter suppression for NSLAR with HPRF. A novel orthogonal-waveform-based elevation adaptive beamforming method is proposed to suppress range-dependent near-range clutter at the first stage, and the residual range-independent far-range clutter is suppressed by azimuth-Doppler space-time adaptive processing (STAP) at the second stage. The proposed elevation beamformer can provide excellent performance on near-range clutter suppression because of the developed secondary data selection strategy. After suppression of the range-dependent near-range clutter, the range independency of clutter samples is enhanced evidently. Hence, the clutter suppression performance obtained by azimuth-Doppler STAP methods could be improved dramatically. Numerical examples are given to verify the validity of the proposed algorithm.