- 學位論文
多星系GNSS精密單點定位技術應用於監測建物牆壁上結構位移之能力分析
Ability Analysis for Monitoring Structural Displacements on The Wall using multi-constellation GNSS Precise Point Positioning Technology
摘要
為了保障人們的生命財產安全，監測建物結構的長期位移與震動位移是重要的。全球導航定位系統（Global Navigation Satellite System, GNSS）之精密單點定位（Precise Point Positioning, PPP）技術無須使用額外的地面主站，並且能夠獲得公分級定位坐標，因此已經廣泛的應用於建物結構位移監測上。考量到衛星遮蔽的問題，衛星接收儀普遍被架設於建物頂端。然而，建物並非剛體，因此必須透過均勻監測建物各個部位，才能獲得整體建物結構的位移，也就是包含建物頂部以及牆壁的部分。 結合多星系 GNSS 可有效提升可視衛星顆數，這使得衛星遮蔽的影響可以被降低。考量到結合多星系 GNSS 的大量可視衛星顆數以及 PPP 技術的優點，結合式 GNSS PPP 技術對於監測建物牆壁上結構位移會是一個有潛力的方法，但是其能力分析未有人提出，因此本研究嘗試使用五星系(GPS/Galileo/GLONASS/BDS/QZSS) PPP 於監測建物牆壁上結構位移並分析其能力，並針對建物結構長期位移以及震動位移兩方面進行探討。 為了保障人們的生命財產安全，監測建物結構的長期位移與震動位移是重要的。全球導航定位系統（Global Navigation Satellite System, GNSS）之精密單點定位（Precise Point Positioning, PPP）技術無須使用額外的地面主站，並且能夠獲得公分級定位坐標，因此已經廣泛的應用於建物結構位移監測上。考量到衛星遮蔽的問題，衛星接收儀普遍被架設於建物頂端。然而，建物並非剛體，因此必須透過均勻監測建物各個部位，才能獲得整體建物結構的位移，也就是包含建物頂部以及牆壁的部分。 結合多星系 GNSS 可有效提升可視衛星顆數，這使得衛星遮蔽的影響可以被降低。考量到結合多星系 GNSS 的大量可視衛星顆數以及 PPP 技術的優點，結合式 GNSS PPP 技術對於監測建物牆壁上結構位移會是一個有潛力的方法，但是其能力分析未有人提出，因此本研究嘗試使用五星系(GPS/Galileo/GLONASS/BDS/QZSS) PPP 於監測建物牆壁上結構位移並分析其能力，並針對建物結構長期位移以及震動位移兩方面進行探討。 分析中，我們採用了架設於透空環境的衛星連續站，考慮到接收儀架設於建物牆壁上將面臨的遮蔽問題，我們刪除了半邊天的衛星觀測量，以及給定了數種不同仰角遮蔽的條件。於長期位移監測的分析中，成果顯示，使用五星系 PPP 在平面方向的能力優於 GPS PPP，並且指出一旦測站的每日解定位精度大於5mm，監測能力將會明顯降低。於震動位移監測的分析中，我們產生的模擬震動位移呈現於GNSS觀測量上，並透過快速傅立葉轉換來分析震動位移的監測能力。成果顯示，使用五星系 PPP 的監測能力優於 GPS PPP，在平面方向的監測能力優於高程方向，以及偵測高頻震動位移的能力優於低頻震動位移。除此之外，我們額外提出了一種具有位置約制條件的 PPP(Constrained PPP, CPPP)來改善傳統 PPP 於震動位移監測的能力。成果顯示，使用 CPPP 能夠更進一步的改善監測微小振幅震動位移(e.g., 0.5cm左右)的能力。
並列摘要
The monitoring of structural long-term and vibration displacements is important to the safety and property of people. Since GNSS (Global Navigation Satellite System) PPP (Precise Point Positioning) requires only one receiver and the positioning accuracy is centimeter-level, it has been widely applied to the monitoring of structural displacements. Considering the satellite blocking effect, a receiver regularly is set on the top of a structure. However, since a structure is not a rigid body, in order to obtain the displacements on the whole structure, it’s required to set receivers evenly on the structure, including on the wall. The number of visible satellites of combined GNSS has been much more than that of GPS. It is helpful to alleviate the satellite blocking effect. Considering the advantages of PPP technology and the great number of visible satellites provided by combined GNSS, combined GNSS PPP technology is a potential means to the monitoring of structural displacements on the wall. Since the ability analysis has not been proposed yet, the study try to use five-constellation GNSS (GPS/Galileo/GLONASS/BDS/QZSS) PPP to monitor structural displacements on the wall and analyze the ability of the monitoring. The monitoring of structural long-term and vibration displacements are discussed in the study. In the analysis, measurements are collected from continuous GNSS stations which are set in open-sky environments. Considering the satellite blocking effect when setting the receiver on the wall, we remove certain satellites by different cut-off azimuths and cut-off angles. In the analysis of the long-term displacements, the result shows that the ability of using five-constellation GNSS PPP is better than that of GPS PPP in horizontal direction. Moreover, when the sigma of PPP daily solution is greater than 5mm, the ability will decrease obviously. In the analysis of the vibration displacements, the vibration displacements are simulated in the measurements. Then, we use fast Fourier transform to analyze the ability. The result shows that the ability of using five-constellation GNSS PPP is better than that of GPS PPP. Moreover, a constrained PPP (CPPP) is proposed to improve the ability of monitoring. The result shows that CPPP can improve the ability of monitoring small vibration displacements (e.g., 0.5cm).