GEO导航卫星定轨观测模型

Orbit Determination Models of GEO Navigation Satellite

根据GEO导航卫星的轨道特性,给出了严密的伪距观测和载波相位观测数学模型;讨论了其轨道和星钟差的解算条件,以及多星组差定轨的可行性。结果表明:在利用伪距时,如果测站钟差已知,需要4个以上站的数据才能进行定轨和星钟解算;如果站钟、星钟钟差已知,需要3个以上站的数据才能确定轨道。在利用站间组差伪距时,须有4个以上测站的钟差信息才能进行轨道和星钟解算;利用GEO卫星与MEO(IGSO)卫星组差定轨时,需要GEO卫星钟差已知且有3组星间组差数据。利用GEO卫星载波相位观测资料,不能单独解算轨道。

The rigorous mathematic models of pseudo-range and carrier phase observation were introduced for navigation satellites, and the conditions of orbit determination and clock solution of GEO were discussed in details. The feasibilities of GEO orbit determination with no-difference observations or difference observations with other satellites, GEO, MEO, IGSO were analyzed as well. The following conclusion could be reached： based on pseudo-range observations of GEO, more than 4 station observations were required to determinate orbit and solute the satellite clock with accurate station clocks information, or more than 3 stations were required with accurate clocks information of both the satellite and the stations. Based on stations-difference-observations, more than 4 stations with accurate clock information were required. Based on satellites-difference-observations, the orbit determinations GEO could be reached only with accurate GEO satellite clock information and more than 3 groups of satellites-difference-observati-ons. The orbit determination can＇ t be reached only by carrier phase observations.