星下点和距离模糊点的回波会降低高分辨率宽测绘带星载合成孔径雷达(SAR)成像质量，使用数字波束形成技术(DBF)可以使天线方向图在对应方向形成零陷以进行抑制。现有的多零点DBF处理技术难以在星上实现，为了将DBF-SAR成像技术工程化，提出一种改进的工程上可实现的俯仰向多零点DBF实时处理方法。该方法对回波信号实时加权，使用LDLT分解迭代解决多零点实时权重生成中面临的线速矩阵求逆问题，从而抑制星下点回波和距离模糊以增加波位选择范围。通过多点目标仿真验证了该实时处理方案的有效性。
崔泽楷
,
肖灯军
,
邱劲松
. 一种改进的面向星上处理的SAR俯仰向多零点数字波束实时形成技术[J]. 中国科学院大学学报, 2025
, 42(6)
: 781
-791
.
DOI: 10.7523/j.ucas.2024.013
The echoes of the nadir and the range ambiguity point will degrade the quality of high-resolution wide mapping band satellite-based synthetic aperture radar (SAR) imaging, and the use of digital beam forming (DBF) can make the antenna directional map to form a null in the corresponding direction for suppression. It is difficult to implement the existing multi-zero-points DBF processing technology on the satellite. In order to engineer DBF-SAR imaging technology, this paper proposes a set of improved engineering-achievable real-time multi-zero DBF processing method in elevation, which weights the echo signals in real time, and solves the inverse line velocity matrix problem faced in the real-time multi-zero weight generation by using the LDLT decomposition iteration to inhibit the Nadir echoes and range ambiguity in order to increase the range of the wave-position selection. The effectiveness of this real-time processing scheme is verified by multi-point target simulation.
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