衛星定位技術隨著全球定位系統(Global Positioning System, GPS)的發展，衛星導航使用者對於服務之品質要求也逐漸提高，然而，此項技術在山區、都市等遮蔽嚴重之環境下，衛星可視度降低、幾何分布不佳，導致使用者無法獲得可用且連續的導航服務，若能夠整合不同衛星系統之觀測量將有效提升可視的衛星數目、增強衛星幾何強度，進而提高精度、可靠度及連續性。目前全球衛星導航系統(Global Navigation Satellite Systems, GNSS)已漸趨完善，本研究將提出合適的方法整合GPS、GLONASS及BeiDou三大系統，以改善自主導航服務的效能；並設計在不同遮蔽程度的觀測環境下，分析GPS/GLONASS/BeiDou整合系統單點定位之表現。本研究收集靜態觀測模式下之電碼觀測量，利用最小二乘法處理平差問題以獲得未知參數之最佳估值。資料處理部分，本研究採用Pope (1976)所提出的 測試，透過假說測試來偵測粗差並加以剔除；並透過Helmert 方差分量估計 (Variance Component Estimation, VCE)的方法，估計不同衛星系統觀測量適當的權比例關係，使多系統整合後能夠有最佳的成果。由實驗成果可知：透過VCE估計各系統間的權比例關係，不同系統的觀測量得以獲得適當的權重，整合式系統的定位成果相較於以等權方式整合的成果要改善許多；從衛星可視度的表現顯示，在受遮蔽的環境下，GPS/GLONASS/BeiDou三系統仍能夠提供相當充足的可視衛星並增加了衛星分布的幾何強度，進而大幅地改善定位之精確度。由此可知GPS/GLONASS/BeiDou整合式系統應用於都市或受遮蔽環境下的必要性，使用者才能獲得更為精確且連續的導航服務。

With the developments of satellite positioning technology, the demand for high-quality navigation service is increasing. However, the technology is easily affected by limited satellite visibility and poor satellite geometry, especially in obscured areas. In order to provide continuous global positioning capability, the usage of multiple GNSS constellations is an effective method for solving the visibility and geometry problem thanks to the increased number of visible satellites. Thus, the goal of this study is to propose a method of integrating GPS, GLONASS, and BeiDou systems for improved autonomous navigation as well as to analyze the improved performance. In addition, a variety of observational conditions are simulated by adjusting satellite cut-off elevation angles. The Pope Tau test is adopted for data blunder detection to prevent the solution from being affected by outliers; furthermore, the Helmert variance component estimation (VCE) is applied to properly model the weighting of the heterogeneous data from different satellite systems. The results show that the VCE is effective in improving positioning accuracy. Moreover, multiple GNSS is adopted so that the GPS/GLONASS/BeiDou integrated system is capable of providing sufficient visible satellites and strengthened satellite geometry. Consequently, the positioning accuracy of the integrated system is greatly improved especially in the obscured environments. It can be known that it is essential to use multiple GNSS in urban or signal-blocked areas so as to ensure the users good autonomous navigation service.

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