学术论文

      伪距波动原因中的星体多径因素排除

      Exclusion of Spacecraft Internal Multipath among Pseudorange Variation Reasons

      摘要:
      针对卫星可视弧段内伪距测量异常波动现象,从信号质量监测角度研究了卫星可视弧段内导航信号测距偏差变化问题,确认伪距波动是否由星体多径引起.利用大口径天线跟踪北斗卫星,采用两套采集设备实现了卫星可视弧段内的B1频点信号多次高载噪比采集,根据基于参考波形的测距偏差估计方法分别处理多组采集数据,获得了不同仰角上的测距偏差.在一个仰角下的采集数据,当滤波器带宽远远大于信号带宽时,采样率与下变频器均不同的两套采集设备获得的测距偏差相同,且测距偏差均与相关间距及滤波器带宽有关,但当滤波器带宽超过15 MHz后,测距偏差的差异可以忽略.比较不同仰角下的测距偏差,在卫星可视弧段内测距偏差变化很小,因此认为星体多径引起卫星可视弧段内信号质量的变化不是伪距测量异常波动的原因.
      Abstract:
      For the code pseudorange variations in the satellite's visible range,ranging bias variation of navigation signal is studied from the point of view of signal quality monitoring,and it's consistency with the code pseudorange variations is confirmed.By using of large antenna to track COMPASS satellite,multiple high CNR B1 signal are collected by two data acquisition platforms.The collected data are processed separately according to ranging bias estimation method based on reference waveform,and ranging biases in different elevation angles are obtained.For one elevation angle,when filter bandwidth is much larger than signal bandwidth,the ranging biases are same for the two data acquisition platforms with different sampling rate and down converter.The ranging biases are both related with correlator spacing and filter bandwidth.However,the difference of ranging bias can be omitted when filter bandwidth is larger than 15 MHz.Furthermore,ranging biases of different elevation angle is compared,and the results show that the difference of ranging biases is tiny.Therefore,signal quality changes in satellite's visible range induced by spacecraft internal multipath is excluded from pseudorange variations.
      Author: GAO Shuai XU Yun YANG Huafeng LIU Jiancheng
      作者单位: 北京卫星导航中心 北京100094
      刊 名: 空间科学学报 ISTICPKU
      年,卷(期): 2017, 37(4)
      分类号: TN95
      在线出版日期: 2017年8月30日