A Self-Calibration Imaging Method for Microwave Staring Correlated Imaging Radar With Time Synchronization Errors

Microwave Staring Correlated Imaging (MSCI) technology has attracted increasing attentions for its ability to acquire high-resolution images in staring imaging geometry. The key point of MSCI is to construct the temporal-spatial stochastic radiation field which can be realized by multi-transmitter systems emitting frequency-hopping (FH) waveforms. However, time synchronization errors always exist in practice, which heavily deteriorates the imaging results. Therefore in this article, a two-step self-calibration imaging method for MSCI transmitting frequency-hopping waveforms is proposed to directly estimate the time synchronization errors. At the first step, a sparsity driven algorithm is proposed which utilizes a novel cluster sparse prior to improve the imaging performance. At the second step, a self-calibration operation is proposed the first time to directly compensate the time synchronization errors in MSCI. By alternately reconstructing the targets and estimating the time synchronization errors, the proposed method can reconstruct the target with high imaging quality and effectively compensate the time synchronization errors. Numerical simulations demonstrate the potential advantages of the proposed method to enhance the imaging quality and improve the time synchronization error estimation performance.