Study on MIMO-SAR System Based on Space Time Coding and Elevation Digital Beamforming

Inhalt:
MIMO-SAR, which employs multiple antennas to transmit orthogonal waveforms and receive echoes, is used to achieve high resolution wide swath. However, the imaging quality is seriously impaired by range ambiguity. A novel MIMO-SAR system combined with Alamouti space-time coding (ASTC) and digital beamforming (DBF) both in azimuth and elevation, named DBF-ASTC-MIMO-SAR, is proposed in this paper. Although echoes corresponding to different ASTC sub-pulses are received in the same receive window, they can be separated by elevation receive DBF. The innovative system is able to decrease the PRF, decrease the effect of time-varying channel response, and reduce range ambiguity.