CAJ | 학술논문

圆迹合成孔径雷达(CSAR)高分辨率成像，对惯导系统的精度和稳定性提出了更高的要求，运动补偿技术是关键技术之一。该文首先分析了轨迹测量误差引起的相位误差，然后针对相位误差的空变性给出一种基于定标器相位梯度提取的圆迹 SAR 轨迹重建方法。该方法从 SAR 回波数据中提取定标器沿方位向的相位梯度，结合多个定标器的相位梯度，利用三边测量法重建高精度圆迹SAR轨迹，用于获取高质量的CSAR图像。该方法解决了轨迹测量误差引起的图像散焦问题，可实现整个场景的有效聚焦。仿真结果验证了该方法的正确性和有效性。
원적합성공경뢰체(CSAR)고분변솔성상，대관도계통적정도화은정성제출료경고적요구，운동보상기술시관건기술지일。해문수선분석료궤적측량오차인기적상위오차，연후침대상위오차적공변성급출일충기우정표기상위제도제취적원적 SAR 궤적중건방법。해방법종 SAR 회파수거중제취정표기연방위향적상위제도，결합다개정표기적상위제도，이용삼변측량법중건고정도원적SAR궤적，용우획취고질량적CSAR도상。해방법해결료궤적측량오차인기적도상산초문제，가실현정개장경적유효취초。방진결과험증료해방법적정학성화유효성。
Circular SAR (CSAR) high resolution imaging requires a more accurate and stable Inertial Navigation System (INS), therefore motion compensation is one of the key technologies. In this paper, the phase error caused by trajectory measurement error is firstly analyzed. Then, the CSAR trajectory reconstruction algorithm based on the extraction of calibrators’ phase gradient is proposed. This algorithm is aiming at the spatial variant property of phase errors. The azimuth differential phase of each calibrator is extracted from SAR echo data. The high precision CSAR trajectory is reconstructed via trilateration in combination with multiple calibrators’ phase gradient. The high quality CSAR image is formed with this trajectory. The proposed algorithm solves the problem of image defocusing by trajectory measurement error, meanwhile the entire scene gets focused efficiently. The simulation results verify the correctness and effectiveness of the proposed algorithm.