GNSS空间信号质量分析方法研究

导航信号质量的优劣,直接关系到卫星导航系统的性能,同时也反映了卫星有效载荷的工作状态和各种电性能指标.中国科学院国家授时中心的GNSS空间信号质量评估系统,以标准仪器监测、离线数据分析和监测接收机三种方式对导航信号质量进行分析与评估.本文主要介绍了该系统的离线数据分析方式和数据采集方法,分析了信号功率谱、眼图、星座图和码片赋形等性能,分析了相关峰、相关损耗等相关性能参数.分析结果表明,该系统中使用的信号质量评估方法实用有效.

Methods of analysis for GNSS signal quality

GNSS signal quality directly impacts to the performance of satellite navigation system, it also reflects the operating state of payload and the indicators of signals. National Time Service Center’s GNSS signal quality assessment system was designed to collect essential information on GNSS signals quality. The 7.3 meter dish antenna is used to take L band measurements. Using the toolset, the typical communication related parameters are evaluated, such as PSD, scatter, eye-diagram, code shape, and vector diagram, etc; the navigation related parameters are computed, like correlation peak curve and navigation messages. The parameters derived from the correlation function, like correlation-loss, are analyzed.