Distributed array radar system high precision jamming cancellation method based on sub-sampling interval time delay compensation

The distributed array radar system can effectively suppress the mainlobe jamming based on the high angle resolution provided by multiple independent radars. However, the excessively large equivalent aperture size may lead to time delay errors from system time asynchrony because the distance between the independent radars are too far. The jamming cancellation performance will severely decline when these time delay errors exist. Precision of traditional compensation methods such as the correlation method are limited by the sampling interval, and other methods such as the sub-band beamforming method cannot completely eliminate the influence of time delay errors either. In this paper, a new method is proposed to compensate for the sub-sampling interval time delay in the distributed array radar system to improve jamming cancellation performance. In the proposed method, the receiving signal of each radar is processed in frequency domain to overcome the precision limitation. Then the linear fitting method is utilized to reduce influence of noise to achieve high estimation accuracy. Simulations and experimental results illustrate the effectiveness of the proposed method on distributed array radar system jamming cancellation.