頁籤選單縮合
題名 | 空載光達DoD與兩期雷射點分佈關係之探討=A Study on the Relationship between DoD and Distribution of LiDAR Point Clouds |
---|---|
作者 | 鐘郁翔; 徐偉城; 劉進金; 謝正倫; 謝明霖; 陳俞旭; Chung, Yu-shiang; Hsu, Wei-cheng; Liu, Jin-king; Shieh, Chjeng-lun; Shieh, Ming-lin; Chen, Yu-shiu; |
期刊 | 航測及遙測學刊 |
出版日期 | 20160500 |
卷期 | 20:3 2016.05[民105.05] |
頁次 | 頁201-216 |
分類號 | 440.98 |
語文 | chi |
關鍵詞 | 遙測; 空載光達; 高精度航測; 侵蝕與淤積; 防災; Remote sensing; Airborne LiDAR; High resolution photogrammetry; Natural disaster; Sedimentation; |
中文摘要 | 空載光達可有效的紀錄地貌特色,產生高精度之數值地形(DEM),故以DoD法(DEM of Difference)進行地形變化分析,DoD乃利用兩期高精度DEM相減後所得,是含高程差值之三維模型。此方法已經是研究地貌演變、集水區土砂產生、以及崩塌地量體等一個重要的分析方法。唯DoD之不確定性並非全區一致, LiDAR DEM品質主要決定於DEM產製過程相關條件,因此LiDAR DEM成果的誤差在每一個地點是不一樣。本研究之目的即在於探討光達點雲分佈不一致產生的DoD品質問題。 本研究以曾文水庫試驗區,利用LiDAR(光達)於2012年1月與2012年10月所產製之兩時期DEM進行地形變化的土方不確定分析。結果顯示直接使用DoD推估地形變化土方計算,全區DoD之不確定性等級最大的部分佔總面積59.49%,不確定性等級最大的範圍內地面點數量是極少的。因此,直接使用DoD推估地形變化土方,其結果將包含極大的誤差值。為確保LiDAR DEM在應用分析上的正確性,須對多時期LiDAR地面點進行DoD之分析評估。 |
英文摘要 | Airborne LiDAR is an effective tool for recording details of landscape and producing high-resolution digital elevation models (DEM). Therefore, DoD (DEM of Difference) method a straight-forward method for conducting volumetric change of two different time with multitemporal DEMs. And, DoD becomes a basic tool for the analyses of landscape change, erosion and sedimentation, volume of landslides, and others. Nevertheless, the accuracy or quality of a DoD cannot remain the same for every grid pixels. For effective application, the main challenge is to understand and suppress the uncertainties caused by this quality problem. The purpose of this study is to explore the uncertainties caused by un-even distribution of point clouds and thus to propose a method using ground points to assess the uncertainties of DoD. The study area is located in Tseng-Wen Watershed of southern Taiwan. Two Airborne LiDAR surveys were conducted in January and October of 2012, respectively. The results show that 59.49% of the area of a DoD is under high uncertainties within which the number of ground points of a grid cell is low. High uncertainties and high risk can take place if volumetric measures are taken from these areas. An alternative approach for suppress the uncertainties is to apply a stencil of polygons generated from manual edited bare lands. Consequently, only 5.55% of the area of a DoD is under high uncertainties. It is concluded that using ground points of multi-temporal LiDAR survey, uncertainty can be effectively assessed to assure the quality of LiDAR DEMs and applications. |
本系統之摘要資訊系依該期刊論文摘要之資訊為主。