GNSS/Pseudolites导航定位中的伪卫星优化模型研究

STUDY OF PSEUDOLITES OPTIMIZATION MODEL IN GNSS/PSEUDOLITES NAVIGATION AND POSITIONING

针对GNSS/Pseudolites组合系统的伪卫星优化布设问题,指出了多指标评价体系下的GNSS系统中伪卫星加入的必要性,构建了基于方位角、高度角及观测历元的多指标评价体系四维模型,并通过实测数据进行实验分析,结果表明:伪卫星的加入所带来的可见卫星个数及低高度角处信息的变化可有效地增强系统的可靠性,提高了系统的定位精度;全景显示下的PDOP值与内可靠性值的最优区域变化相似但分布不同;PDOP、内可靠性、耗资等多因素约束的综合定权可有效协调各个指标,为选择最优系统提供可靠依据并在全景显示下有效地解决伪卫星优化GNSS系统的高效选址问题。

Aiming at optimal construction of pseudolites in GNSS/Pseudolites （PLs） combined system, this pa- per pointed out the necessity of PLs＇ joining in GNSS, and built a four-dimensional（4-D） model based on azimuth angel, elevation angel and observed epochs. Then, an experiment was taken to test the model, and the results show that the increasing number of visible satellites and the changing information of low-elevation satellites can enhance the reliability of the system and improve positioning accuracy. Panorama shows that variations of the PDOP value and the reliability value within the optimal region are similar but the distributions are different. The weight con- strained by the PDOP, internal reliability, cost and other factors can be effective coordinate indexes for selecting optimal system and provide reliable basis for effectively solving the problem of locating PLs for GNSS/PLs optimiza- tion.