BDS, GPS, GLONASS, Galileo and QZSS多衛星系統組合對定位精度影響之分析

The Study of Analysis the Influences of Positioning Accuracy for Combination of Multi-Satellite System Observations

本研究利用北斗導航衛星（BeiDou Navigation Satellite System, BDS）觀測資料，與GPS（Global Positioning System）、GLONASS（Global Navigation Satellite System）、Galileo和QZSS（Quasi Zenith Satellite System）等全球導航衛星系統（Global Navigation Satellite System, GNSS）觀測量結合，利用多頻衛星接收儀獲取多系統結合之衛星訊號，並設計不同長短基線的網形實驗，分別為長基線靜態觀測及短基線半動態與RTK（Real-Time Kinematic）觀測試驗進行處理，將多衛星系統組合之觀測資料，進行計算與比較分析，探討其對定位精度之影響與提出最佳化之分析報告。在現階段之條件下，本研究成果顯示，在靜態觀測中，多衛星系統之PDOP（Position Dilution of Precision）值較單一系統為低，但未必能提升觀測精度；但短基線觀測成果在高程或平面精度部分上，均優於長基線觀測之成果。在動態觀測中，顯示結合多衛星系統在進行觀測時，其衛星幾何分布較佳，則有更佳的定位精度。在本實驗中，當GPS或GLONASS觀測成果不佳時，多衛星系統的增加使觀測的成功率上升。在動態定位觀測實驗上，半動態觀測較RTK成果提升精度上更為明顯。在動態觀測上，多衛星系統的觀測位於透空良好的地帶成效也許不明顯，但觀測品質不佳的地點，因加入多衛星系統，使其觀測成果就有明顯的改善，顯示多衛星系統若能配合適當網形平差模式，能使穩定性大幅提升，進而縮短觀測時間，說明基於觀測品質的考量，不同區域仍須選擇適當測量方法。

This research is combined BDS data with GNSS observations, including GPS, GLONASS, Galileo and QZSS satellite signals, by multi-frequency satellite receivers. Designed experiments of various-baseline nets, Static measurements on long baselines and semi-kinematic and RTK measurements on short baselines. For combined multi-satellite system observation, to compare and analysis the influences of positioning accuracy in optimization report.Under current conditions, the results of those studies are summarized as follow. On static measurement test. Multi-satellite system could not be able to enhance the accuracy of the observation. Not only in horizontal but also in vertical components, result shows that the accuracy on short-baseline measurements are better than the results of the long-baseline measurements.On kinematic measurement test. Because of geometric distribution, multi-satellite system maybe expressed more positioning accuracy during working.In this study, if the accuracy of only GPS or only GLONASS system observations expressed poor status, combined with multi-satellite systems could be enhanced probability of success in the kinematic measurement test, especially for semi- kinematic measurement.On kinematic measurement test. For multi-satellite system data, probability of success maybe not very obviously varied in open areas, but probability of success clearly varied in poor quality observation areas.This work shows that and more accuracy of positioning could be achieved and time of observation could be reduced by multi- satellite data with suitable network adjustment model, especially for semi- kinematic measurement. Based on the observed quality considerations, it proved when different areas still need to select the appropriate measurement methods.