CAJ | 학술논문

在地形起伏较大的山地区域，星载SAR利用传统俯仰向数字波束形成(DBF)方法接收场景回波时，都会出现波束指向偏差的问题，这一偏差使得回波接收增益与信噪比降低。针对这一问题，该文提出一种基于Capon空间谱估计的星载SAR自适应DBF方法。该方法首先通过有限的回波数据来准确地估计出各距离门内信源的波达角(AOA)，而后利用这些信息来更新接收波束的加权矢量，从而能够在任何时刻都使接收波束准确地指向信源位置，以此来改善回波增益与信噪比。仿真实验结果表明，该方法较传统的俯仰向波束扫描(SCORE)法有较大的性能改善，同时它还对系统及信源参数的变化有很强的鲁棒性。
재지형기복교대적산지구역，성재SAR이용전통부앙향수자파속형성(DBF)방법접수장경회파시，도회출현파속지향편차적문제，저일편차사득회파접수증익여신조비강저。침대저일문제，해문제출일충기우Capon공간보고계적성재SAR자괄응DBF방법。해방법수선통과유한적회파수거래준학지고계출각거리문내신원적파체각(AOA)，이후이용저사신식래경신접수파속적가권시량，종이능구재임하시각도사접수파속준학지지향신원위치，이차래개선회파증익여신조비。방진실험결과표명，해방법교전통적부앙향파속소묘(SCORE)법유교대적성능개선，동시타환대계통급신원삼수적변화유흔강적로봉성。
In rough mountainous areas, beam-pointing mismatch problems always arise when a spaceborne Synthetic Aperture Radar (SAR) uses the traditional Digital BeamForming (DBF) approach in elevation to receive echoes, leading to the degradation of the receiver’s gain and system Signal-to-Noise Ratio (SNR). To solve this problem, an Adaptive Digital BeamForming (ADBF) approach based on the Capon spatial spectrum estimation is proposed. This approach first estimates the Angle Of Arrival (AOA) of the source signal in each range bin using the limited echo data. Then, it updates the weighting vector in the beamforming process, thereby enabling the receiving beams to precisely point to the signal source, and enhance the receiver’s gain and SNR. Simulation results suggest that the ADBF approach significantly improves the performance compared to the SCan-On-REceive (SCORE) approach, exhibiting robustness to system and source parameters variations.