GPS天线相位中心改正方法研究

由于天线本身的特性及机械加工等原因,GPS卫星和接收机天线相位中心与其几何中心不重合,从而产生相位中心偏差。某些类型的天线该偏差甚至可达数cm,直接影响高精度GPS测量的精确可靠性[1]。讨论了GAMIT软件在高精度GPS数据处理中进行天线相位中心改正的原理、方法和策略,结合美国IGS观测站及南加州区域站观测数据,对改正方法及策略进行了实验对比与分析。结果表明:对接收机天线相位中心和卫星天线相位中心采用模型改正,而卫星天线相位中心偏移不改正,所得到的基线解算结果较好[2];地面接收机天线方位角的变化对U方向的基线解算结果有较大影响,在高精度GPS测量中,必须进行天线方位角的变化改正。

Research on the Corrections Method of GPS Antenna Phase Center

Due to the characteristics of the antenna itself and machining, GPS antenna phase center cannot coincide with its geometric center, resulting in phase center offsets. The deviation is usually about several millimeters, ever up to a few centimeters for some types of antennas, with a direct impact on the effectiveness of high-precision GPS measurements This essay mainly discussed the principles, methods and strategies of antenna phase center corrections on the process of high-precision GPS data processing with the use of GAMIT. Based on the American IGS Observatories and the observed data from the Southern California, the essay did experiment on, made a contrast of and analyzed the corrections and strategies. Experimental results indicate that better handling accuracy can be obtained by adopting the correcting model on the receiver antenna phase center and satellite antenna phase center, without the correction of satellite antenna offset. In addition, correction of the ground receiver azimuth also makes a great influence on the experimental results.