Using Close-Range Photogrammetry to Reconstruct Digital Terrain Model of Post-Disaster Slopewithout Artificial Targets

• Main Authors: Wan-Ting Chung, 鐘琬婷
• Other Authors: 張哲豪
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/29qfb2

碩士 === 國立臺北科技大學 === 土木與防災研究所 === 99 === Spatial technology has undergone rapid development in recent years. In laser scanning technology as well as aerial and terrestrial photogrammetry, highly accurate three-dimensional data can now be acquired in relatively short time. Taiwan is a place prone to calamities such as earthquakes, heavy rainfall and typhoons, which in turn result in highly unstable slope conditions and landslides. This study targets the area of Houshanyue behind Zhinan Temple Station of the Moakong Gondola in Muzha as a site of interest. Our purpose is to develop measurement methods which require minimal manpower and resources and in the meantime ensure personnel safety; this can facilitate instant documentation of three-dimensional data at disaster sites. Three-dimensional models constructed from such data can in turn be utilized for display and measurement purposes, providing immediate information from the sites of disaster and also material for subsequent study and analysis. This study introduces a close-range photogrammetry method without artificial targets. We acquired feature point coordinates via total station measurement and performed software-assisted model reconstruction of slopes at disaster sites. To evaluate the accuracy of slope models, accuracy verification was focused on two aspects: single-point measurement accuracy and model accuracy. For the first aspect, among the control point coordinates obtained from the total station, five control points were selected and altered to checkpoints of non-solving exterior orientation, and the residuals on the model and between checkpoints were thus calculated. As for model accuracy verification, models generated via high accuracy ground LiDAR measurement served as standards for comparison of two different models. Final results were displayed in the form of Virtual Reality Modeling Language (VRML).