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

Abstract

Clutter suppression is a challenging problem in non-side-looking airborne radar (NSLAR) because of the rangedependent 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.

Clutter Suppression Approach for End-Fire Array Airborne Radar Based on Adaptive Segmentation

“…Whereas for EAAR, the three-dimensional clutter ridges are all distributed on a certain plane and the elevation spatial frequencies of the clutter ridge in the same range are different. Hence, the elevation-dimensional pre-filtering methods [15]- [17] which filter out short-range nonstationary clutter by forming an adaptive elevation notch will completely fail for EAAR. Meanwhile, the conventional twodimensional, i.e., azimuth-Doppler dimension, clutter ridges of the two systems are elliptical and have serious range dependence in short range, but the long-range clutter tends to be stationary.…”

Clutter suppression algorithm for non‐side looking airborne radar with high pulse repetition frequency based on elevation–compensation–prefiltering

“…The near‐range clutter always overlaps with the far‐range clutter in this case, and the above methods cannot avoid the mainlobe of the elevation beamformer from distortion. In order to avoid the impact of far‐range clutter, two algorithms with improved training sample selection strategy are proposed in [22, 23], respectively. The efficient elevation‐domain adaptive (EEDA) method proposed in [22] selects the elevation training sample just from the return corresponding to the first pulse.…”

An Overview on Time/Frequency Modulated Array Processing

“…In fact, the ability to control rangedependent transmit energy distribution becomes an increasingly desirable feature in applications such as range-dependent interference suppression [2]- [4], directional communications [5] and range ambiguity suppression [6]- [8]. To address the current needs, many advanced array design ideas have appeared in the literature.…”