星间相位干涉仪测角系统设计及精度分析

针对微小卫星编队飞行、星间组网等多星协同任务中的相对测角问题，提出了一种高精度的星间无线电测角系统。该系统的优势是在伪码测距系统的基础上增加两条相同的接收通道，对载波相位值采用相位干涉法得到高精度的星间相对角度值，可以在不增加额外软硬件开销的情况下完成实时性较好的高精度星间相对状态自主测量。从该系统的设计出发，对相位干涉仪测角系统进行了详细的精度分析，推导了链路中各个噪声源的传递函数和理论噪声水平，并搭建实物平台对角度测量精度的理论值和实测值进行比较。结果表明系统对本振相位噪声有抑制作用，热噪声是角度测量的最大噪声源，系统实际测角精度在强信号下可达1.4×10^-3度。

Design of inter-satellite phase interferometer angle measurement system and its precision analysi

Aiming at the problem of relative angle measurement in multi satellite cooperative missions such as satellite formation flying and inter-satellite networking,a high-precision radio angle measurement system was proposed.It was realized by adding two same receiving channels on the basis of PN code ranging system.The system used carrier phase combined with phase interferometry to obtain high-precision inter-satellite relative angle.The advantage of the system is that it can complete the real-time and high-precision inter-satellite relative state autonomous measurement without additional hardware and software overhead.Starting with the design of the system,a detailed precision analysis of the phase interferometer angle measurement system was carried out.Then the transfer function and theoretical noise level of each noise in the link were derived.A physical platform was built to compare the theoretical value and the measured value of the angle measurement accuracy.The results show that the system has a suppressive effect on the phase noise of the local oscillator,and thermal noise is the largest noise source for angle measurement.The angle measurement accuracy of the system can reach 1.4×10^-3 degrees under strong signal conditions.