| 摘要: | 近年來合成孔徑雷達干涉技術(InSAR)廣泛地應用於地表測量與監測，具有空間辨識率高、覆蓋 範圍大、地表形變敏感度高，以及不易受天候影響等優點。Hopper等人(2004)提出的永久散射體雷達干涉測量法(PS-InSAR)，藉由影像中反射特性穩定的點位增加相位計算品質與精度，但在進行雷達影像匹配時需要達到相當的衛星影像才能找到足夠的散射體點位，其解算後的點位於山區分佈相較不足。過去不少學者針對大屯火山活動性進行相關研究，例如地震監測、地球化學分析、地殼變形與地溫量測等，大屯火山觀測站的設置突顯了全面性進行火山活動觀測的重要性。因此，我們提出了綜合性的科學研究，包括地形、構造、遙感和大地測量，以台灣大屯火山為研究區域，使用多時序時域相關點雷達干涉技術(MT-InSAR)，配合日本衛星雷達影像(ALOS/PALSAR, ALOS2)L波段SAR數據，可以穿透高植被覆蓋區域，同時TCP-InSAR 技術改善傳統合成孔徑雷達影像分析方法，在植被茂密的山區有效觀測點數量過少的問題，可得到大面積的地表資料，並將地表GPS連續觀測資料納入TCP-InSAR之解算，將其分析成果提高至公釐(mm)級精度。最後，利用大地測量資訊(水準測線)進行變異量率定，並配合高精度數值地形模型搭配地形與地質資料，探討區域內地表變形的分佈概況與相關成因。
Interferometric Synthetic Aperture Radar (InSAR), which has been widely applied to the measurement and monitoring of surface ground deformation over the last couple of years, features high spatial resolution, big coverage, high sensitivity to displacement, and all-weather availability. The Persistent Scatterer InSAR (PSInSAR) proposed by Hooper et al. (2004) can enhance the phase measurement quality and accuracy by extracting persistent scatterers (PSs) with stable reflectivity. However, this technique requires considerable radar images to find sufficient PSs, which appear to be rather insufficient in mountain areas. A number of scholars have already conducted a research on the activity of Tatun Volcano, such as earthquake monitoring, geochemical analysis, crustal deformation and geothermal measurement. The establishment of Tatun Volcano Observatory therefore highlights the importance of conducting an observation of volcanic activity in all perspectives. We therefore propose a comprehensive scientific research that studies Tatun Volcano from topography, tectonics, remote sensing and geodesy. In this project, we have adopted the Temporarily Coherent Point InSAR (TCPInSAR) to, together with L-band SAR data of Japan's satellite radar images (ALOS1 and ALOS2), effectively increase the number of effective observation points. As the L-band signal penetrates deeper into the vegetation canopy and TCPInSAR provides an enhanced solution comparing with traditional SAR tools, we will be able to acquire surface ground deformation data over an extensive area. Besides, continuous GPS data can also be included to enhance the TCPInSAR results to the precision of millimeter (mm) level. Finally, geodesic data (GPS, leveling ) have been used for variation rating. Together with high-precision digital elevation model (LiDAR-DEM) as well as topographic and geological data, the distribution of surface ground deformation within the regions and triggering factors will be discussed. |
