earticle

영어

In this paper, we introduce an innovative scanning synthetic aperture radar (SAR) termed as the Hybrid Phased-MIMO SAR (HPMSAR) and investigate the system performance. The HPMSAR overcomes the limitations imposed by the conventional scanning SAR (ScanSAR, spotlight SAR, or Terrain Observation by Progressive Scans (TOPS) SAR) and presents the strong flexibility in imaging mode. Every subarray in HPMSAR is simultaneously pointed in the different directions and electronically steers the azimuth beam. This not only increases the illumination time per subswath entailing a high azimuth resolution but also covers an ultra-wide swath giving short-term time for global coverage. However, multidirectional scanning imaging will produce overlapped echoes and ambiguities on receive, then this paper presents the advanced processing scheme based on two-dimension (2-D) digital beamforming (DBF) with multichannel unambiguous reconstruction technology. The key of this method lies that multichannel processing technology in azimuth ensures receiving echoes free of aliasing by using a low PRF, and 2-D DBF could effectively suppress ambiguities and separate the overlapped echoes from different subswaths. Performance analysis compared with traditional methods shows output performance of interference suppression.