A Wide-swath High-resolution Imaging Mode for MIMO InSAR without Transmitting Orthogonal Signals

The ability to reconstructing the terrain height profile of MIMO InSAR outperforms the ordinary multibaseline InSAR. One key technology of MIMO InSAR is the echo separation on the receiver. The available orthogonal signals introduce great cross-interferences between different MIMO Channels due to their inadequate orthogonality. An equivalent MIMO InSAR imaging mode without transmitting orthogonal signals is presented in this paper, whose echo separation do not depend on the orthogonality of transmitting signals. Instead, the elements of this MIMO InSAR system transmit alternately in different pulse duration under this mode, hence the mainlobe echoes of different transmitting signals appear in different pulse duration coordinately. The cross-interferences are suppressed sufficiently with low sidelobe transmitting pattern in elevation. Furthermore, the multichannel azimuth processing based ScanSAR technique is employed in this MIMO InSAR imaging mode to improve its swath width and azimuth resolution. The numerical simulations prove the validation of the proposed mode.