建立永久散射體雷達干涉技術與傾斜管所量測邊坡位移之關係–以臺北貓空纜車沿線邊坡地區為例

Establishment of Slope Displacement Relationships between PSInSAR and Inclinometer Measurement – Case Study of Taipei Maokong Slope

顏筱穎(Hsiao-Ying Yen)

指導教授 ： 楊國鑫

國立臺灣大學/工學院/土木工程學研究所/碩士(2021年)

https://doi.org/10.6342/NTU202102733

摘要

台灣位處板塊交接處，因板塊活動劇烈，七成以上之土地屬於山坡地，這些山坡地因地質條件多較為破碎。此外，在汛期常有梅雨或是颱風伴隨而來之強降雨，便容易引發波地災害。坡地監測，即是最有效能夠評估坡地穩定性之方法。傳統上較常使用單點式測量，如水準測量、傾斜管等等。隨著遙測科技之發展，干涉合成孔徑雷達(Interferometric Synthetic Aperture Radar, InSAR) 技術開始廣泛的被利用在量測地表變形上。相較於傳統量測受人力及機械之限制，InSAR技術利用衛星重複軌道之特性，能夠不受天氣影響，大範圍獲取同一地區長時間之高精度的地表變形資訊。
本研究利用永久散射體雷達干涉(Persistent Scatterer InSAR, PSInSAR)技術，使用了2015至2016年間之Sentinel-1A昇軌及降軌之SAR影像，獲取台北貓空纜車系統沿線之山坡地衛星視線方向的位移情形，利用鄰近之GPS連續測站校正PSInSAR之成果，並將其轉換為邊坡方向，以現有傾斜管資訊作為驗證。其結果顯示，在分析期間，邊坡上之PS點的位移速度位於-7至13mm/year，且PSInSAR結果與傾斜管讀數有相同趨勢；藉由比對PS點與傾斜管坐落邊坡之特性，探討PSInSAR結果與現地量測之差異。透過統計分析，建立永久散射體雷達干涉技術與傾斜管所量測邊坡位移關係，其倍率分別為0.99及1.29. 此外，利用此位移關係，本研究欲提供一基於InSAR技術之邊坡管理值，可供邊坡早期預警之注意值及警戒值使用；然，因短時間之PSInSAR位移仍有無法避免之跳動情形，故不適用於行動值。

關鍵字

邊坡位移 ； Sentinel-1 ； 干涉合成孔徑雷達 ； 永久散射體雷達干涉技術與傾斜管之關係

並列摘要

Monitoring is the most effective method to assess slope stability and its behavior. Interferometric Synthetic Aperture Radar (InSAR) technology provides a monitoring method to detect ground surface deformation. Different from the traditional way, this measurement is not restricted by location and weather. It can image in a wide region regularly with high resolution. Persistent Scatterer InSAR (PSInSAR), the subsequent development of InSAR techniques, is a powerful tool to measure ground surface deformation in the long-term period. However, the vegetation-covered and forested weakens the performance of PSInSAR.
The slope in the Taipei Maokong area was studied because the in-situ instrument along the Taipei Maokong Gondola system is plentiful. In this work, through the PSInSAR process of sentinel-1A data, this research obtains the displacement from 2015 to 2016. The density of PSs near the slope of Maokong Gondola is enough. The velocity of displacement ranges from -7 to 13 mm/year in slope direction. The PSInSAR result shows the same displacement trend as the inclinometer reading. Besides, the displacement can identify the type of movement of the slope. Finally, the relationships between the PSInSAR and inclinometer measurement are 0.99 and 1.29 times using ascending and descending data, respectively, and discuss the discrepancy between these two methods.

並列關鍵字

Slope displacement ； Sentinel-1 ； PSInSAR ； The relationship between PSInSAR and inclinometer

參考文獻

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