First results of BDS positioning for LBS applications in the UK

The last satellite of BeiDou Navigation Satellite System with Global Coverage(BDS-3)constellation was successfully launched on June 23rd,2020,and the entire system began to provide Positioning,Navigation,and Timing(PNT)services worldwide.We evaluated the performance of location services using BDS with a smartphone that can track the Global Navigation Satellite System(GNSS)satellites in Nottingham,UK.The static and kinematic experiments were conducted in an open meadow and a lakeside route covered by trees,respectively.Experimental results show that BDS has good visibility,and its overall signal carrier-to-noise density ratio(C/N0)is comparable to that of Global Positioning System(GPS).The average C/N0 of BDS-3 satellites with elevation angles above 45°on B1 band is the highest among all systems,reaching 40.0 dB·Hz.The noise level of the BDS pseudorange measurements is within 0.5 m,and it has a good consistency among satellites.In the static experiment,the standard deviations of BDS position-ing in the east,north and up directions are 1.09,1.16,and 3.02 m,respectively,and the R95 value of the horizontal position is 2.88 m.In harsh environments,the number of BDS satellites tracked by the smartphone is susceptible to environmental factors.The bias Root Mean Squares(RMS)in the three directions of the whole kinematic positioning are 6.83,6.68,11.67 m,in which the positioning bias RMS values in a semi-open environment are only 2.81,1.11,3.29 m.Furthermore,the inclusion of BDS in multiple GNSS systems can significantly improve the positioning precision.This study intends to provide a reference for the further improvements of BDS global PNT services,particularly for Location-Based Services(LBS).