北斗三号卫星系统总体设计

对于全球导航卫星系统(global navigation satellite system, GNSS), 观测值测距性能会影响系统基本服务能力。大口径抛物面天线能够较好地削弱地面设备和环境对信号采集的影响。基于抛物面天线数据分析北斗三号全球卫星导航系统(BeiDou-3 global navigation satellite system, BDS-3)的观测值特性和测距性能。结果显示, B1I、B3I、B1C、B2a和B2b 5个频点上均未发现与北斗二号卫星类似的相同量级卫星星上伪距偏差, 部分频点伪距多路径存在波动, 但与高度角的相关性不强, 所有卫星测距偏差变化的平均量级为0.1 m。使用载波三频组合分析北斗三号卫星各个频率载波观测值的多路径变化和噪声水平, 载波三频组合存在毫米量级的变化波动, 但这种变化并未显示出与时间或者高度角的密切相关性, 基于抛物面天线数据的载波三频组合均方根误差绝大部分小于0.6 mm。以上结果表明北斗三号卫星的伪距和载波观测值未出现系统性偏差, 具有良好的测距性能。

General Design of the Third Generation BeiDou Navigation Satellite System

  Objectives  For global navigation satellite system(GNSS), the ranging performance of observation would influence the system service capability.  Methods  Parabolic antenna with large-diameter could greatly reduce the impact of the ground equipment and the environment on signal acquisition. Based on data from parabolic antenna, observation characteristics and ranging performance of BeiDou-3 global satellite navigation system(BDS-3) are analyzed.  Results  The results show that, regarding the pseudorange deviation on BeiDou-3 satellite, no systematic deviation of the same magnitude, compared with BeiDou-2, is found on the signal of B1 I, B3 I, B1 C, B2 a, and B2 b. There are fluctuations on some signals. However, the correlation with elevation angle is not strong, and the average magnitude of all satellite fluctuations is 0.1 m. This paper analyzes the multipath variation and noise level of carrier observation for BeiDou-3 satellite of each signal using triple-frequency combinations. The fluctuations of carrier phase triple combination are of the millimeter level, and those fluctuations do not closely correlate with the elevation or time. The root mean square of the triple-frequency carrier combination from parabolic antenna is mostly less than 0.6 mm.  Conclusions  The results indicate that no systematic bias occurs in code and phase observation of BDS-3, and the system has a good ranging performance.