航天器DOR信号本地相关处理的建模与仿真

Modeling and Simulation of Local Correlation Processing of Spacecraft DOR Signals

详述了DOR（差分单向测距）信号的本地相关处理方法。首先根据轨道预报确定先验时延模型值,利用高精度频率估算方法估计航天器DOR信号的星上发射频率,然后通过时延模型值与频率估计值构造DOR本地模型信号,再将此模型信号分别与测站接收的DOR实测信号进行互相关运算,提取相关相位,解算高精度时延观测量。推导了DOR信号本地相关处理的数学模型,通过信号仿真验证了该方法的有效性,在仅考虑系统噪声影响与轨道预报误差的条件下,仿真时延测量精度达到0.1 ns,为深空航天器精密轨道测量提供了一种可借鉴的技术方法。

The local correlation processing method of DOR （Differential One-way Ranging） signal is introduced in detail. First, a priori delay model is calculated with orbit forecasts and the on-board emission frequency of DOR from the spacecraft is estimated with high-accuracy frequency estimation method. Then, the delay model and estimated frequency are used to construct the DOR local model signal, and the correlation phase is extracted through cross-cor- relation processing. The mathematical model for DOR signal local correlation processing is deducted. The method is validated through signal simulation. Simulation delay measurement accuracy is about 0.1 ns when only the effect of random noise and orbit forecast error are taken into consideration. This provides a support to a technical approach for precise measurement of deep-space spacecraft.