基于北斗系统的水面无人艇在远洋地区定位性能分析

Assessing the over ocean positioning performance of unmanned surface vehicle based on Beidou satellite navigation system

为了评估水面无人艇在远洋地区的卫星导航定位性能,从可见星数量、PDOP值以及定位精度等多个方面对BDS及其组合导航系统的定位效果进行分析。本文给出单点定位的数学模型与方法,结合GPS真实广播星历参数和BDS全星座仿真数据,对远洋地区的4个测站进行定位性能分析。结果表明,在南海海域BDS系统的GEO卫星长期可见,定位精度显著优于GPS系统,水平方向和高程方向分别可达2 m和4 m;在南极罗斯海海域BDS系统的GEO卫星和高仰角卫星不可见,水平方向和高程方向分别可达3 m和6 m,定位精度略优于GPS系统;GPS+BDS组合定位系统在4个测站能保证可观测卫星在20颗左右,不仅能够提高系统的可靠性,还大大提高了定位精度。

In order to evaluate the satellite navigation and positioning performance of unmanned surface vehicle in ocean area,the positioning effect of BDS and its integrated navigation system is analyzed from the aspects of number of visible satellites,PDOP values and positioning accuracy.In this paper,the mathematical model and method of single point positioning are presented.Combined with GPS actual broadcast ephemeris parameters and BDS full constellation simulation data,the positioning performance of four stations in the ocean area is analyzed.The results show that the BDS GEO satellites in the South Sea are long-term visible,and the positioning accuracy is significantly better than that of the GPS system,with the horizontal and vertical directions reaching 2 m and 4 m respectively;the GEO and the high elevation angle satellites in the Antarctic Ross Sea area are invisible,with the horizontal and vertical directions reaching 3 m and 6 m respectively,and the positioning accuracy is slightly better than the GPS system;the GPS+BDS combined positioning system can ensure that the observable satellites are around 20 at four stations,which can greatly improves the positioning accuracy and reliability.