A Downward-looking Three-dimensional Imaging Method for Airborne FMCW SAR Based on Array Antennas

作者：Hou Haiping; Qu Changwen^*; Zhou Qiang; Xiang Yingchun

来源：Chinese Journal of Aeronautics, 2011, 24(1): 55-64.

DOI：10.1016/S1000-9361(11)60007-1

• synthetic aperture radar
• radar imaging
• frequency modulated continuous wave
• downward-looking
• three-dimensional
• array antenna
• digital beamforming

With regard to problems in conventional synthetic aperture radar (SAR), such as imaging distortion, beam limitation and failure in acquiring three-dimensional (3-D) information, a downward-looking 3-D imaging method based on frequency modulated continuous wave (FMCW) and digital beamforming (DBF) technology for airborne SAR is presented in this study. Downward-looking 3-D SAR signal model is established first, followed by introduction of virtual antenna optimization factor and discussion of equivalent-phase-center compensation. Then, compensation method is provided according to reside video phase (RVP) and slope term for FMCW SAR. As multiple receiving antennas are applied to downward-looking 3-D imaging SAR, range cell migration correction (RCMC) turns to be more complex, and corrective measures are proposed. In addition, DBF technology is applied in realizing cross-track resolution. Finally, to validate the proposed method, magnitude of slice, peak sidelobe ratio (PSLR), integrated sidelobe ratio (ISLR) and two-dimensional (2-D) contour plot of impulse response IRF) of point target in three dimensions are demonstrated. Satisfactory performances are shown by simulation results.

• 出版日期2011-2
• 单位中国人民解放军海军航空工程学院