一种基于探测器下行信号融合处理的无线电干涉测量方法

针对深空探测器常用下行信号体制,结合无线电干涉测量特点,提出了一种基于探测器DOR信标信号和数传信号融合处理的干涉测量方法。该方法首先通过相关处理得到DOR信号和数传信号的差分相位,利用DOR信号进行带宽综合得到时延估计,并构建时延模型;然后,利用时延模型得到DOR信号与数传信号在数传载波处的相位差,并以此对数传信号差分相位进行补偿;最后,利用DOR信号差分相位和补偿后的数传信号差分相位进行带宽综合,实现高精度干涉测量。深空探测网数据处理结果表明融合处理后时延估计随机误差明显降低;但受介质时延误差影响,融合处理对系统时延精度的改善幅度有所减小。该方法仅通过改进干涉测量数据处理方法即实现了时延估计随机误差的改善,不仅提高了信号使用效率,而且增强了航天测控系统的鲁棒性,在应急测控背景下具有特殊意义。

A Novel Method of Radio Interferometry Based on Fusion Processing of Explorer Downlink Signal

In view of the commonly used downlink signal of deep space explorer and the characteristics of radio interferometry,a novel interferometry method is proposed to process DOR signal and data-transmission signal simultaneously for frequency synchronization. Firstly, the difference phase of the two kinds of signal is obtained by correlation. While, the time delay is estimated by utilizing DOR signal''s difference phase and is modeled during the processing. Then the phase difference between DOR and data-transmission signal at data signal carrier is acquired by using the constructed time delay model, compensating the difference phase of data-transmission signal. Finally,the difference phase of DOR signal and the compensated difference phase are processed for frequency synchronization and time delay estimation. The processing results of measured data in China deep space TT&C network show that the time delay accuracy is improved significantly by fusion process, while the improvement is decreased lightly with the influence of medium delay error. The proposed method improves the accuracy of time delay estimation just by fusion process, which not only promotes the signal use efficiency, but also enhances the robust of the TT&C system,having special significance in emergency situation.