基于双GPS接收机的精密定向研究

The Study of Precise Orientation Based on Two GPS Receivers

GPS定位系统除了可以进行定位、测速和授时外 ,还可以利用两个或多个GPS测量值进行方位测量和三轴姿态测量。文章对利用两块GPSOEM板同步接收的载波相位观测量来精密测定方位进行了深入研究。首先利用载波相位的双差观测方程 ;再根据两个天线间距离已知这个条件 ,对方位和俯仰进行二维搜索 ,并采用了模糊度函数作为搜索的判断依据 ;最后根据最小二乘计算出两个天线的基线矢量 ,从而最终计算出精密的方位值和俯仰角。经过大量的试验表明 ,该算法是切实可行的 ,在 5m基线下 ,方位精度达到 0 0 8°,而且定向时间一般只需

Two or more GPS receivers can be used to determine the orientation or attitude of objects except that GPS can be used to determine the position, velocity and time. How to determine the orientation precisely based on carrier phase synchronization provided by two GPS OEM boards is studied in depth in this paper. The double difference of carrier phase is formulated first and then the orientation and pitch are searched in two dimensional space based on the baseline between the two GPS receivers. The ambiguity function is used as the judgment criterion to search the azimuth and pitch. At last, the baseline vector of the two GPS receivers is determined using the least square and the accurate azimuth and pitch are calculated based on the accurate baseline vector. Many test results show that the method is feasible and the accuracy can reach 0 08 degree with a 5 meters baseline and it only takes 1 3 minutes to determine orientation in real time.