Qinglong Bao

Robust mainlobe interference suppression for coherent interference environment

A mainlobe interference suppression method is proposed in this paper, which can still work when the signal of interest (SOI) is present in the training data. In this method, the iterative adaptive approach (IAA) is applied to spatial spectrum estimation at first. Then, IAA spatial spectrum is used to reconstruct the interference-plus-noise covariance matrix (INCM). Next, the eigenvector associated with mainlobe interference in INCM is determined, and the eigen-projection matrix can be calculated to suppress the mainlobe interference. Meanwhile, the sidelobe-interference-plus-noise covariance matrix (SINCM) can be reconstructed. Finally, the adaptive weight vector is obtained. One main advantage is that the proposed method can deal with coherent mainlobe interference and sidelobe interferences simultaneously. Simulation results demonstrate the effectiveness and robustness of the proposed method.

An Experimental Study of Passive Bistatic Radar Using Uncooperative Radar as a Transmitter

This letter proposes a signal processing method of passive bistatic radar (PBR) exploiting an uncooperative radar as an illuminator. Compared with other opportunity illuminators, the transmitting signal of a radar usually has a better ambiguity function, which leads to a higher range resolution. Two channels are needed in PBR system. The reference channel is used to estimate radar signal parameters and reconstruct directly propagated signal. The surveillance channel is used to receive scattered wave. An array antenna and a simultaneous multibeam algorithm are necessary in the surveillance channel due to the flexible beam scanning of the uncooperative radar. The procedure of the proposed method is explained in detail, which is then followed by a field experiment. Preliminary results from the field experiment show that the proposed method can be applied to target angle and bistatic range measurement successfully.

Experimental study of uncooperative radar signals as illuminators for passive bistatic radar applications

This paper proposes a signal processing method of passive bistatic radar (PBR) emploiting a phased array radar as an illuminator. Compared with other opportunity illuminators, the transmitting signal of a radar usually has a better ambiguity function, which leads to higher range resolution. Two channels are needed in a PBR system. The reference channel is used to estimate radar signal parameters and reconstruct directly propagated signal. The surveillance channel is used to receive scattered wave. An array antenna and simultaneous multibeam algorithm are necessary in the surveillance channel due to the flexible beam scanning of the phased array radar. The procedure of the proposed method is explained in detail that is then followed by a field experiment. Preliminary results from the field experiment show that the proposed method can be applied to target localization successfully.

A novel detection method based on FrFT for passive radar

In this paper, a novel detection method based on Fractional Fourier Transform is proposed. Compared with the conventional signal processing procedure, the proposed method achieved the similar performance to the matched filter without the estimation of transmitter signal parameters and the reconstruction of transmitted signal. The evaluations of the proposed method are summarized.

Efficient mainlobe interference suppression in coherent multipath environment

A mainlobe interference suppression method is proposed in this paper, which can still work when the signal of interest (SOI) is present in the training data. In this method, the iterative adaptive approach (IAA) is applied to spatial spectrum estimation at first. Then, IAA spatial spectrum is used to reconstruct the interference-plus-noise covariance matrix (INCM). Next, the eigenvector associated with mainlobe interference in INCM is determined and the eigen-projection matrix can be calculated to suppress the mainlobe interference. Meanwhile, the sidelobe-interference-plus-noise covariance matrix (SINCM) can be reconstructed. Finally, the adaptive weight vector is obtained. One main advantage is that the proposed method can deal with coherent mainlobe interference and sidelobe interferences simultaneously. Simulation results demonstrate the effectiveness of the proposed method.

Acoustic Radar Weak Target Detection Method Based on Mellin Transform

Acoustic radar has the advantages of low cost, high resolution, and the simplicity for sampling and storage. Recent years, it has been widely studied and applied in fields such as target detection, recognition and imaging. However, the sound signal is usually wideband. The wideband correlation function is often used in active and passive detections. To address the problems of the errors and computational burden introduced by approximation and the interpolation of signal dilation, a Mellin transform based multi-pulse weak target detection method is proposed. The method can reduce the Mellin sampling numbers and the detection result can be updated pulse by pulse.