一种GPS移动基准站精密相对定位新算法

针对GPS载波相位差分定位中差分基准站不能移动的问题,提出了一种GPS移动基准站精密相对定位的方法.该算法首先基于MW组合构造几何无关测量值,然后对几何无关测量值进行滑动平均滤波消除随机噪声影响,在移动站进入移动基准站数据链覆盖范围时进行站间和星间双差处理获得宽巷整周模糊度,并结合载波相位的双差几何相关模型建立Kalman滤波观测方程,将多路径误差建模为1阶Gauss-Markov随机过程,作为状态参数纳入状态方程,增广状态向量,同时扩增观测方程,从而滤波获得L1/L2模糊度浮点解的精确估计,最后采用LAMBDA算法搜索固定模糊度的整数解.通过静态和车载动态实测试验验证了新算法的正确性和适用性.

A Novel GPS Precise Relative Positioning Algorithm for Moving Base Station

Aiming at the issue of immobility of differential reference station in GPS carrier phase differential positioning, an algorithm of GPS precise relative positioning for moving base station is proposed in this paper. Firstly, geometry free measurements are structured based on Melbourne-Wubbena combination, which are then filtered by moving average filter to remove the influence of random noise. The double difference processing is adopted to further eliminate common error when dynamic user comes into the data link coverage of moving base station, and then the wide lane ambiguities are obtained. At this time, Kalman Filter observation equation is established in combination with carrier phase double difference geometry based model. Then multipath error is modeled as first order Gauss-Markov random process and brought into state equation as augmented state parameters, thereby accurate estimate of float solution of L1/L2 ambiguity can be obtained. Lastly, the LAMBDA method is used to search the fixed ambiguity. In order to test the algorithm, static and vehicle dynamic tests are conducted according to designed accuracy verification scheme, and centimeter level accuracy of relative positioning is obtained, which may be applied to precise dynamic relative navigation such as carrier aircraft landing, autonomous aerial refueling, spacecraft rendezvous etc.