GEOSAR相位定标附加相位估计方法  

A Motion Additional Phase Estimation Method for GEOSAR Phase Calibration Signal

作　　者：张浩龙[1,2,3] 江冕[1,2,3] 朱雪莹[1,2,3] 胡文龙[1,2] 

机构地区：[1]中国科学院空间信息处理与应用系统技术重点实验室,北京100190 [2]中国科学院电子学研究所,北京100190 [3]中国科学院大学,北京100049

出　　处：《雷达科学与技术》2015年第4期410-414,420,共6页Radar Science and Technology

摘　　要：地球同步轨道合成孔径雷达(GEOSAR)相位定标系统由于其运行于地球同步轨道之上,因而会存在弱信噪比的问题,而对信号进行相干积累是一个提高信号信噪比的有效办法。首先分析了卫星轨道运动对于相干积累过程的影响,尤其是在长时间积累过程中,卫星的轨道运动会给GEOSAR相位定标信号增加一个非线性的附加相位调制,利用容积卡尔曼滤波的方法,能够在非线性较强的条件下对附加相位依旧有较高的估计精度,并在此基础上构造匹配滤波器对信号进行匹配滤波,实现信号的相干积累。Due to geosynchronous synthetic aperture radar（GEOSAR） phase calibration system operat- ing on the earth synchronous orbit, the SNR of the received signal is too low to extract phase information ac- curately. However, applying coherent accumulation to low-SNR signal would be an effective method to im- prove SNR. This paper first analyzes the influence of the satellite orbit motion on the process of coherent ac- cumulation, especially in the long period of accumulation. The satellite orbit calibration signal would be add- ed a nonlinear phase modulation, which would influence the process of coherent accumulation. The cubature Kalman filtering method is used. The method bears a higher estimation accuracy for additional phase estima- tion even in the situation of strong nonlinearity. On the basis of our additional phase estimation, we construct a matching filter to process our low-SNR signal for realizing coherent accumulation.

关 键 词：相位估计 相干积累 卡尔曼滤波 合成孔径雷达 

分 类 号：TN959.74[电子电信—信号与信息处理] TN958[电子电信—信息与通信工程]