以空載光達校正場矩形平屋頂半自動評估點雲精度之程序研究

THE STUDY OF SEMI-AUTOMATIC ACCURACY ASSESSMENT PROCEDURE ON POINT CLOUDS USING RECTANGULAR PLANAR ROOFS FROM AIRBORNE LIDAR CALIBRATION FIELD

邱式鴻(Shih-Hong Chio) ； 詹立丞(Li-Cheng Chan)

《中國土木水利工程學刊》 32卷1期 (2020/03) Pp. 49-61

https://doi.org/10.6652/JoCICHE.202003_32(1).0005

摘要

以空載光達校正場矩形平屋頂作為標的物執行點雲精度評估時，需先萃取平屋頂面上之點雲，為避免萃取成果受雜訊影響，本研究引入粗差偵測理論，發展最小一乘法[1]結合李德仁所發展以後驗變方估計原理導出的選擇權迭代法（稱李德仁法）[2]將非屋頂點視為粗差排除。研究中使用校正場6組點雲資料，經由測試提出半自動化點雲精度評估之程序。實驗結果顯示本研究所提之程序，其成果可避免因人而異，達一致性之點雲精度評估結果；而實驗結果亦顯示，本研究所提最小一乘法結合李德仁法的改良李德仁法，可將非屋頂點視為粗差排除，於含有大量牆面點雲的資料中，比原李德仁法提升約10%的偵測粗差數量。

關鍵字

點雲精度評估 ； 最小二乘平面擬合 ； 粗差偵測 ； 最小一乘法 ； 選擇權迭代法

並列摘要

This study attempts to establish a semi-automatic procedure for the accuracy assessment of point clouds from airborne LiDAR system. Least Absolute Deviation (LAD) [1] combined with the Iteration using selected weights presented by Li (Li method) [2] is developed to exclude the non-roof points that are regarded as gross errors and eliminate their influences. In this study, six datasets in calibration field were used to develop a semi-automatic procedure based on several tests. Even different operators employ this semi-automatic procedure, consistent results were obtained and the reliability can be achieved in this study. In additional, about 10% gross errors can be detected by our proposed improved Li method than original Li method.

並列關鍵字

point clouds accuracy assessment ； least squares plane fitting ； gross error detection ； least absolute deviation ； iteration with the selected weights