Then, GPS error sources and their influences on positioning accuracy are analyzied. Moreover ,we simulated the GDOP changes along the whole trajectory to decide the best poiont for GPS receiver to start working.

• 本文分析了高动态情况下GPS误差源对定位精度的影响，并且对全弹道GDOP进行仿真，以此说明接收机最佳工作时段的选择。