An improved BP algorithm for high-resolution MIMO imaging radar

The back-projection (BP) algorithm is a popular imaging method. Nevertheless, there exists a difficulty that the cross-range resolution acquired by the standard BP algorithm is dependent on the bandwidth of transmitted signal when the BP algorithm is directly used to the multiple-input multiple-output (MIMO) radar for imaging a target in the cross-range direction without any variation. In this paper, an improved BP algorithm is presented for high-resolution MIMO imaging radar to avoid the difficulty associated with the standard BP algorithm. Furthermore, the theoretical expression of the cross-range resolution associated with the improved BP algorithm is given. Different from the standard BP algorithm, the cross-range resolution acquired by the presented BP algorithm can be independent on the bandwidth of transmitted signal since the presented algorithm can straight an integration curve and make the received echoes on the integration curve be focused by phase aligning to avoid the truncation error produced by the range resolution value. Simulations based on synthetic data are provided for testing the presented method.