旋转干涉仪定位体制系统误差标校方法

Calibration method of rotating interferometer positioning system

除了信号噪声原因带来的相位差随机误差,旋转干涉仪定位体制中相位差的测量误差主要包括由通道幅/相不一致、载荷与转台时间不同步、基线旋转平面与卫星平台本体非共面等因素引入的相位差系统误差。系统误差的大小直接决定了定位结果偏离真实位置的程度,为了减小系统误差对定位精度的影响,通过对旋转干涉仪相位差进行建模,将系统误差等效为转角偏差、倾角偏差、横滚角偏差和通道偏差四个校正量的影响,利用迭代最小二乘参数估计算法,提高校正量参数估计的准确性,从而提升系统定位的性能。

In addition to the random error of phase difference caused by signal noise,the measurement error of the phase difference in positioning mechanism based on rotating interferometer are mainly includes inconsistent amplitude and phase in the same channel,the time between payload and turntable out of sync and the non-coplanar situation between rotation plane of baseline and the satellite’s platform.All these problems will lead to the systematic error of phase difference,and the size of the systematic error directly determines the extent to which the positioning result deviates from the true location.In order to reduce the influence of systematic error on positioning accuracy,the systematic error is equivalent to the influence of the three correction parameters of the rotation angle deviation,the pitch angle deviation,the roll angle deviation and the channel deviation by modeling the phase difference of rotating interferometer.Finally,the iterative least squares estimation algorithm is used to improve the accuracy of the estimation of the four correction parameters,so as to promote the positioning performance of the system.