弱信号下BDS接收机卫星信号发射时间恢复方法

发布时间：2018-01-16 08:38

本文关键词：弱信号下BDS接收机卫星信号发射时间恢复方法　出处：《中南大学学报(自然科学版)》2014年10期 　论文类型：期刊论文

【摘要】：传统的GPS弱信号定位算法存在对本地概略位置和时钟精度要求高的问题。针对这一不足,提出一种混合星座分步解算的弱信号定位算法。首先通过GEO观测数据将用户位置误差压缩到20 km,降低算法对本地时钟精度要求,其次加入非GEO卫星改善DOP值,计算接收机精确位置。相对于传统弱信号定位方法,本文算法将接收机本地时钟精度要求,理论上可由187.5 s增大至1 500s。B1频点实测数据分析结果表明:当无法获得较准确概略位置时,本文方法可将本地时钟偏差允许范围提高达2h以上;与传统方法相比,可以在最不利的情况下,减少近一半的初次信号发射时间整秒模糊搜索的计算量。
[Abstract]:The traditional GPS weak signal localization algorithm has the problem of high local approximate position and high clock precision. In this paper, a weak signal location algorithm for hybrid constellation is proposed. Firstly, the user position error is reduced to 20km by GEO observation data, which reduces the local clock precision of the algorithm. Secondly, the non-#en0# satellite is added to improve the DOP value, and the precise position of the receiver is calculated. Compared with the traditional weak signal localization method, the local clock accuracy of the receiver is required by this algorithm. Theoretically, the measured data can be increased from 187.5 s to 1 500 s.B1 frequency point. The results show that: when a more accurate approximate position can not be obtained. This method can increase the allowable range of local clock deviation to more than 2 hours. Compared with the traditional method, the first signal transmission time can be reduced by nearly half of the time of the whole second fuzzy search in the worst case.
【作者单位】：国防科技大学电子科学与工程学院;
【基金】：教育部新世纪优秀人才支持计划项目(NCET-08-0144)~~
【分类号】：TN96.1
【正文快照】： 导航接收机通过测量卫星信号发射时刻结合本地时间确定伪距值,从而完成定位解算任务。卫星信号时间一般由导航电文确定的毫秒级以上整数时间及伪码相位测量获得的毫秒级以内的时间共同组成[1-2]。但由于存在遮挡、森林衰减、信号干扰等,接收机收到信号载噪比衰减可能达到10~35

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