Joint high resolution imaging and autofocusing technique via an iterative method for multistatic passive

The performance of the multistatic passive radar imaging system (MPRIS) based on illuminators of opportunity is not as good as traditional SAR/ISAR due to the narrow bandwidth of the radiated signal and the unevenly distribution of the non-cooperation illuminators. Moreover, the inaccurate position measurement of illuminators, receivers and the target would cause phase errors in the target echo and the quality of the image would further subject to degradation. With the motivation to improve the performance of the MPRIS, an imaging algorithm based on the principle of tomographic imaging is presented. On account of the sparse distribution of the scatterer of the target, the compressed sensing algorithm is extended to the multistatic configuration to realize the super resolution image formation. In addition, an autofocusing technique based on the multistatic observation model is proposed. By defining a quality measure of the image, the phase error is found by iteratively solving an equation which is derived by optimizing the quality measure of the image. The convergence and performance of the presented autofocusing technique have been validated by simulation results.