目前北斗卫星导航系统在轨卫星共有13颗,处于试运行阶段,亚太地区已经具备了实时定位能力。首先,根据武汉地区的实测数据,初步分析当前系统卫星的可见性。然后,针对北斗系统短基线相对定位,提出了合适的模糊度搜索算法。根据武汉地区的北斗/GPS双系统实测数据,进行北斗系统单历元模糊度固定及基线解算,并将模糊度固定结果及基线解算精度与GPS系统进行对比。结果表明,对于15km以下的短基线,北斗系统单历元模糊度固定成功率超过80%;单历元基线解算精度比GPS系统稍低,在平面方向可达3cm,高程方向可达6cm。
The Beidou navigation satellite system has been in trial operation since last year, and will provide services in China and its surrounding areas at the end of 2013. We first ana- lyze the system's satellite visibility in Wuhan, and discuss the Beidou ambiguity resolution (AR) algorithm for short baseline. Experiments were conducted using the dual-frequency GPS/Beidou data collected in Wuhan and processed with GPS and Beidou system separately. The preliminary results indicate that the current Beidou system has the ability of precise po- sitioning capacity. For the short baseline (4 15 kin) of the Beidou system, the success rate of single epoch ambiguity resolution reaches 80%. The final positioning precision is better than 3 cm on the horizon, and is better than 6 cm for elevation.