Azimuth Multichannel GMTI Based on Ka-Band DBF-SCORE SAR System

• Published in: IEEE geoscience and remote sensing letters Vol. 15; no. 3; pp. 419 - 423
• Main Authors: Wang, Hui, Zhang, Hui, Dai, Shoulun, Sun, Zhiqiang
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 01.03.2018; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Algorithms; Along-track interferometry (ATI); Antenna arrays; Antennas; Azimuth; Beamforming; Coefficients; Conflicts; Data; Data acquisition; digital beamforming (DBF); Direction; Directive antennas; displaced phase center antenna (DPCA); Estimation errors; ground moving target indication (GMTI); High gain; Interferometry; Moving targets; Multichannel communication; multichannel SAR; Procedures; Radar; Receiving antennas; SAR (radar); scan on receive (SCORE); Synthetic aperture radar; Transmitting antennas
• ISSN: 1545-598X; 1558-0571
• DOI: 10.1109/LGRS.2018.2791622

The azimuth multichannel synthetic aperture radar (SAR) system is used in ground moving target indication (GMTI). But for Ka-band SAR, the conflicts between high gain and wide swath coverage are very strict. The digital beamforming (DBF) scan-on-receive (SCORE) algorithm can solve this problem very well. This letter introduces a multichannel SAR system with three receiving antennas in the azimuth direction. For each azimuth antenna, eight subapertures are arranged in the elevation direction in order to obtain higher gain and a lower data rate through the DBF-SCORE algorithm. Airborne flight experiments with this system are accomplished successfully and quantities of experimental data are acquired. In this letter, we first derive the signal forms and weighting coefficients in the DBF-SCORE procedures. Then, different GMTI methods including along-track interferometry and displaced phase center antenna are introduced for azimuth multichannel SAR-GMTI based on the DBF-SCORE technology. Finally, airborne raw data with cooperating moving targets are processed successfully, and the estimation errors of the radial velocities meet the expected accuracy requirements.