地基MIMO雷达快速成像算法研究

Fast Imaging Algorithm Based on Ground-Based MIMO Radar

地基多输入多输出(Multiple-Input Multiple-Output,MIMO)成像雷达采用数字波束形成技术实现二维成像,具有成像速度快的技术优势。本文提出了一种适用于大景深、宽视角场景的地基MIMO雷达的快速二维成像算法。首先,根据MIMO雷达的阵列构型建立回波信号模型;其次,基于该模型补偿天线阵列近场空变性的相位中心近似(Phase Center Approximation,PCA)误差并进行数据重排,通过Kesytone变换校正距离徙动;然后,利用方位分块Dechirp处理实现方位向聚焦,实现MIMO雷达二维成像;最后利用MIMO雷达外场实验数据完成了算法验证。研究结果表明:在保证成像精度要求的情况下,该算法可以实现大景深、宽视角场景的高分辨快速成像,成像处理时间优于反向投影成像(Back Projection,BP)算法。

Ground-based Multi-Input Multi-Output (MIMO) imaging radar uses digital beamforming technology to achieve two-dimensional imaging, with the advantage of fast imaging speed. A kind of fast two-dimensional imaging algorithm for MIMO Radar which is applied to large depth of field and wide viewing scene is proposed. First, establish the signal model based on array configuration of MIMO radar;Second, compensate Phase Center Approximation (PCA) error with spatial variability based on the model and make data rearrangement, correct the Range Migration by the Keystone transform;Then, the azimuth focusing was realized by the Dechirp processing of the divided sub-blocks, and thus the MIMO radar image with good focusing performance was obtained. The imaging algorithm was verified by real echo data obtained from the field experiment. The research results show that high resolution imaging of large depth of field and wide viewing scene can be achieved under the condition of ensuring imaging accuracy, and the operation speed is obviously better than Back Projection (BP) algorithm.