Application of Topographic Openness for Self-developed Three-dimensional Terrain Maps and GPS Survey

• Main Authors: Yu-Sin Jheng, 鄭鈺馨
• Other Authors: Yu-Shen Hsiao
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/ga77mx

碩士 === 國立中興大學 === 水土保持學系所 === 106 === This thesis analyzes the topographic openness applied to self-developed three-dimensional terrain maps and global positioning system (GPS) positioning accuracy. The topographic openness has been studied in the past 20 years. It is mostly used for topographic map generation and landslide interpretation. We provide two methods of computing topographic openness, the average method and the eight-direction method, to analyze their difference in creating the self-developed three-dimensional terrain maps. In addition, the relationship between the topographic openness and the GPS positioning accuracy is analyzed. The test areas include urban areas and hillsides. In the self-developed three-dimensional terrain maps, the topographic openness derived from the eight-direction method show a better result than those derived from the average method because it can present more detailed terrain. In GPS positioning, the topographic openness corresponding to the PDOP values are more reasonable than the average method. Therefore, we recommend using the eight-direction method in the GPS survey. This study analyzes the results of using different topographic openness calculation methods for creating the self-developed three-dimensional terrain maps. In addition, an important method of determining the hot zone for setting up a GPS station is also provided.