全球定位系统和全球卫星导航系统伪距综合法

论述了综合GPS、GLONASS伪距测量值获取定位信息的滤波方法。GPS、GLONASS的坐标系、时间系统、工作频率不同，不同卫星的方位、高度各不相同，因而其测距的系统误差也各不相同，通常的方法是用GPS和GLONASS的钟差2个参数来描述不同系统卫星的系统误差，需用5颗卫星来定位，且精度受限。采用扩展状态维数，对不同卫星的系统误差进行在线估计的滤波方法，可以有效地改进卫星定位的精度。同时既可以用多星定位，充分利用测量信息，也可在任一系统的l颗卫星可用时，给出测者的最优估计位置信息，改进了双星系统的导航性能。

Method of Combining the Pseudo-Range Measurements of GPS and GLONASS

This paper describes the filter method of combining the pseudo-range measurements of GPS and GLONASS to get observer's position information. Becasue of the differences of coordinate system, time system and working frequency between GPS and GLONASS, and also the difference of azimuth and altitude among all satellites, the system bias of the pseudo-range measurements are different. For traditional methods, 2 clock errors are used to express the pseudo-range bias of GPS and GLONASS, in which 5 satellites are needed for positioning and the precision is limited. The filter method of increasing the dimensions of state vector to estimate bias for different satellites can improve positioning precision effectively, by which not only more satellites can be used to get more position information, but also can get optimum estimated position information to improve the navigation performance of the twin satellite system when one satellite of GPS or GLONASS is used.