多径效应对北斗星间链路载荷校准影响的研究

Influence of multi-path effect on load calibration of inter-satellite links of BDS

北斗导航卫星星间链路的主要功能是卫星、星地的精密测量和数据传输。为了保证测量精度不受温度、器件老化等因素影响,星间链路巧妙地设计了校准系统,而多径信号是影响北斗导航卫星星间链路载荷校准结果的重要误差源,为了进一步优化星间链路校准结果,提高星间链路测量精度,分析了星间链路校准系统多径效应产生的原理,建立了多径信号测量误差仿真模型,通过Matlab仿真分析了多径延迟、多径衰减对时延、幅度和相位测量的影响,评估了不同延迟、不同衰减多径信号对测量误差的定量影响,并根据分析结果对星间链路校准设计给出了一些建议。通过星间链路测试,验证了建议措施的有效性。

The main functions of the inter-satellite links of the Beidou navigation satellite system(BDS)are the precise range measurement and data transmission of the satellites and the satellite to ground. The calibration system is skillfully designed for the inter-satellite links to ensure that the measurement accuracy is not affected by temperature,device aging and other factors.However,the multi-path signals are the important error sources that affect the load calibration results of the inter-satellite links of BDS. In order to further optimize the calibration result of inter-satellite links and improve its measurement accuracy,the principle of generating the multi-path effect in inter-satellite link calibration system is analyzed and the simulation model of multi-path signal measurement error is established. The impact of multi-path delay and multi-path attenuation on the delay,amplitude and phase measurement is analyzed by Matlab simulation. The quantitative effects of multi-path signals with different delays and different attenuations on measurement errors are evaluated,and some suggestions for the calibration design of inter-satellite links are given according to the analysis results. The effectiveness of the proposed measures has been verified by the test of inter-satellite links.