Thirdly , an ideal satellite orbit is simulated , and on this foundation , we establish some typical simulation and testing circumstances . lastly , after simulation in the simulation and testing circumstances , we compare the performance of ukf and ekf . and then , based on the outdoor experiment of the vehicle , an analysis and contrast between our simulation results and commercial data process software is carried out , and the conclusion is obtained 首先在第三章提出的目標運動模型的基礎上建立了系統狀態方程;其次簡要分析了衛星導航系統中的各類誤差,建立了基于偽距觀測量的系統觀測模型;第四節利用yuma格式歷書數據模擬了未受攝動影響的衛星軌道,并在此基礎上建立了幾種典型的動態仿真測試環境;第五節為仿真分析和比較,先對ukf算法和ekf算法在動態仿真測試環境中進行了仿真比較,然后針對外場試驗,對非線性濾波獲得的定位結果與商業軟件進行了分析比較,并得出結論。