GPS精密单点定位收敛时间的影响因素研究与分析

发布时间：2019-02-19 10:30

【摘要】：随着近年来IGS及其分析中心公布的精密卫星轨道和钟差产品的精度不断提高，以及GPS单点定位由于精度较低无法实现高精度定位，差分GPS定位又受作业距离、仪器成本等因素制约的现状。非差精密单点定位技术成为全球卫星定位技术的研究热点，近年来也涌现出大量的研究成果，但其发展存在两方面因素的制约：一是精密单点定位收敛时间较长，，无法广泛普及于工程应用；二是精密卫星星历存在时延性，无法满足实时用户的需求。本文针对精密单点定位收敛时间较长的问题进行探讨分析。首先，简要阐述了精密单点定位的基本原理；然后，探讨了精密单点定位的数据处理方法；最后，通过试验讨论分析了影响精密单点定位收敛时间的因素，并总结出一些可以减少PPP收敛时间的改善措施。通过对影响精密单点定位收敛时间的因素进行算例分析，包括观测数据的质量及采样间隔、精密卫星星历的类型、对流层改正方法及卫星空间几何构型PDOP，得出以下几点有益的结论：（1）接收机类型及硬件延迟偏差对精密单点定位收敛时间的影响甚微。（2）对高纬度地区的测站，用对流层参数估计法进行解算，不仅可以加速精密单点定位的收敛时间，而且可以大幅度提高定位结果的精度。对于中低纬度的测站，在X、Y方向上参数估计的收敛速度与定位精度均明显优于模型改正，在Z方向参数估计和模型改正收敛速度相当。总体来说，参数估计的定位精度和收敛速度均明显优于模型改正。（3）对于采样间隔较小（大于1s）的观测数据，其定位结果的收敛速度相对于采样间隔较大的观测数据有所加快。对于观测时段较长的数据，观测数据的采样间隔对收敛速度的影响较小；对于观测时段较短的数据（一般认为2h之内），观测数据的采样间隔对收敛速度的影响较大。（4）卫星的几何精度因子PDOP不仅与可视卫星数密切相关，而且与卫星星座的几何构型有关。当可视卫星数越多，卫星星座的几何构型越好，相应的PDOP值越小，定位精度越高，其收敛速度越快。
[Abstract]:With the improvement of precision satellite orbit and clock error products published by IGS and its analysis center in recent years, as well as the low precision of GPS single point positioning, the differential GPS positioning can not achieve high precision positioning, and the differential GPS positioning is subjected to the operating distance. The current situation of equipment cost and other factors. Non-differential precise single-point positioning technology has become the research hotspot of global satellite positioning technology, and a large number of research results have emerged in recent years, but its development is restricted by two factors: the first is the long convergence time of precision single-point positioning. Can not be widely used in engineering; Second, the precision satellite ephemeris can not meet the needs of real-time users because of its ductility. In this paper, the problem of long convergence time for precise single point positioning is discussed and analyzed. Firstly, the basic principle of precision single point positioning is briefly described, and then the data processing method of precision single point positioning is discussed. Finally, the factors affecting the convergence time of precise single point positioning are discussed and analyzed, and some improvement measures are summarized to reduce the convergence time of PPP. Through the analysis of the factors affecting the convergence time of precise single point positioning, including the quality of observation data and sampling interval, the type of precise satellite ephemeris, the method of tropospheric correction and the geometric configuration of satellite PDOP,. Some useful conclusions are obtained as follows: (1) the type of receiver and the delay deviation of hardware have little effect on the convergence time of precise single point positioning. (2) the method of tropospheric parameter estimation can not only accelerate the convergence time of precise single point positioning, but also greatly improve the accuracy of positioning results. The convergence speed and positioning accuracy of parameter estimation in XY direction are obviously better than that of model correction for stations in middle and low latitudes. The convergence speed of parameter estimation in Z direction is similar to that of model correction in Z direction. In general, the location accuracy and convergence rate of parameter estimation are obviously superior to those of model correction. (3) for the observation data with small sampling interval (> 1 s), the convergence rate of the localization results is faster than that of the observation data with larger sampling interval. For the data with longer observation period, the sampling interval of observation data has little effect on the convergence rate, while for the data with shorter observation period (generally considered within 2 hours), the sampling interval of observation data has a great effect on the convergence rate. (4) the geometric precision factor (PDOP) of satellites is not only closely related to the number of visible satellites, but also to the geometric configuration of satellite constellations. When the number of visible satellites is more, the geometric configuration of satellite constellation is better, the corresponding PDOP value is smaller, the positioning accuracy is higher, and the convergence speed is faster.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：P228.4

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