Accuracy Validation of the Point Clouds from Airborne Lidar Collected in Two Missions of Different Year in Hsin-Chu Area
| Autor: | Shao - Chen Wu, 吳紹禎 |
|---|---|
| Rok vydání: | 2006 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 94 This study evaluates height and planimetric accuracy of the point clouds collected by two airborne lidar missions in 2002 and 2005 respectively. Ground Check Points were collected utilizing real time kinematic GPS in 2004 and 2005 by a field survey team. After analyzing the differences between these four data sets, it is found that there are significant height offsets between two different flight line groups of the 2002 lidar point clouds. Systematic errors in the 2004 GCPs are also identified. With strip adjustment, the internal consistency of the 2005 lidar data can be improved. However, the external accuracy with the GCPs does not show any improvement. In planimetry, the building boundaries are extracted from the point clouds and compared to a 1:1000 vector map. Hough transform is applied to find corner points for buildings. The errors are then assessed, utilizing both visual and statistical approaches. Experimental results indicate that mean errors were between 0.259m-0.795m in planimetric offsets. The results also show that planimetric offsets in the scanning direction are smaller than those in the flight direction. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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