| Summary: | 碩士 === 國立中央大學 === 遙測科技碩士學位學程 === 102 === Differential Interferometric Synthetic Aperture RADAR (DInSAR) technique has been successfully used to observe the surface deformation with the high spatial resolution. However, a major limitation for measurement is affected by atmospheric propagation delay due to the significant impact on microwave signals. To solve this problem, some methods have been proposed in the past decade years. (1) DInSAR technique combines the optical images to correct the atmospheric delay caused by water vapor. (2) Persistent Scatterer (PS) InSAR technique, which choose the stable scatterers with time series images, estimate and reduce the effects by processing high-pass filtering in time and low-pass filtering in space. The study area is in the Uttarakhand state of Western Himalaya, India, including the geologocal units of Lesser Himalaya, Siwalik Hills and the Ganga plain, India. Because the lack of reseaches and data, geodesy and seismic data, we applied previous techniques in our study area by using the Envisat and MODIS images during the period from 2008-2011. The difference of MODIS PWV between the date shows 0 – 20 percent change and the zenith wet delay maps shows larger value in plain area than the mountain area. After the process of using optical images, MODIS data, the values of displacement are decreased and the deformation pattern of along the Himalaya area is much more reliable. The PSInSAR result shows detail movement related to the tectonic. Both technique results successfully reveal obvious surface deformation, which may be related to the tectonic activity in the region. Final, the sensitivity test of DInSAR and atmospheric data shows the non-linear changes between the atmospheric data and DInSAR result. The atmosphere delay may affect the DInSAR result, but has upper limit.
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