2009-08-012024-05-18https://scholars.lib.ntu.edu.tw/handle/123456789/701178摘要：本計畫擬針對GNSS (Global Navigation Satellite System) 衛星定位之品質評估與網形規劃進行分析與探討，藉由三維地形資訊的引入並配合嚴謹的平差統計模式，以建立一具有高可靠度的衛星定位分析與規劃軟體，進而提升衛星測量工作之品質與效率。 在目前的衛星定位規劃軟體中大多未考慮地形（如高樓或山區地形起伏）所造成之遮蔽效應，而僅以人工設定遮罩角方式來進行衛星可視性與定位精度估計，此簡化方法除了對單點定位品質評估結果產生誤差外，對於差分定位（需多個接收器對多個衛星同時可視）等複雜求解模式更會產生非常顯著之影響。此外在評估衛星定位品質的過程中，衛星軌道經常視為已知控制資訊，然而在實際定位解算時，定位結果將會隨著所採用軌道的良寙而產生不同的成果，因此衛星軌道之品質應該以適當的統計模式反應在定位品質評估中。 隨著空間資訊技術的發達，已使得現今高品質地表三維資訊（如DEM、DSM等）之取得日趨容易，而本研究將建立三維地形資料輔助衛星可視性與網形分佈之分析技術，並因應不同資料解析度與品質需求，發展自適應（adaptive）的取樣分析方式，在兼顧分析品質的前提下有效提升分析演算之效率。此外在求解模式方面，亦透過引入虛擬觀測平差（unified least squares approach）之技術，以合理的統計模式反應衛星軌道之品質，進而提升精度評估成果之可靠度。最後本研究將所發展之技術建立一套完整的分析軟體，並進行實際測試以驗證其可靠度。預計本研究成果將可直接應用於衛星測量外業規劃軟體中，具有產業化應用之潛力。 <br> Abstract: This proposed project is focused on the quality analysis of a GNSS satellite surveying. By introducing three-dimensional topographic information and utilizing rigorous mathematic and statistical analysis models, a GNSS quality analysis and project planning software is to be developed with a goal to improve the reliability and efficiency of a satellite surveying field work. In the current satellite surveying analysis software, the satellite visibility and positioning quality are typically determined without taking into account topographic masking effects caused by high buildings, mountains, etc. Consequently, the analysis result may be inaccurate. This impact becomes more significant for complicated satellite positioning models, for instance, a DGPS in which multiple satellites should be simultaneously visible from multiple receivers. Furthermore, a satellite’s orbit is typically treated as known quantity and its uncertainty is seldom considered while accessing the positioning quality. However, any satellite orbit comes with various levels of uncertainties and should be reasonably reflected in a analysis result. Fostered by the rapid development of spatial information technique, three-dimensional topographic information (e.g., Digital Terrain Model and Digital Surface Model) of a higher quality can be easily obtained. The major emphasis of this research is thus on developing a satellite visibility and quality analysis technique using high quality 3-D topographic information. An adaptive sampling and analysis technique will be proposed to increase the computational efficiency while processing topographic data of various resolutions and accuracies. Additionally, a unified least squares approach will be introduced to model the uncertainties of satellite orbits and thus to improve the reliability of the quality assessments. Finally, all the techniques developed in the research will be integrated into a GUI software and field tests will be performed to verify its capability and reliability. Upon finishing this project, the fruit can be readily applied in actual satellite surveying project planning software and has a high industrial potential in the near future.衛星定位衛星可視性遮罩角數值地形模型幾何精度因子Global Navigation Satellite SystemSatellite VisibilityMask AngleDigital Terrain ModelDilution of Precision