Abstract: 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.

Key words: inter-satellite relative state measurement, phase interferometer, angle measurement system, precision analysis, channel imbalance