應用GNSS－－RTK技術在古蹟工程3D LiDAR雷射掃描之研究

Comparison and Analysis of GNSS-RTK Combined with 3D LiDAR Technology on Monument Maintenance Project

藉由國定古蹟李騰芳古宅建築為例，本研究提出新的思維，即是利用結合多衛星測量技術（GNSS靜態觀測、e-GNSS、和GNSS-RTK），用以取代傳統控制測量的實施。利用此新的作業方法，對古蹟點位定位精度與觀測時間的影響進行分析與研究，並結合此作業模式，對古宅全區作雷射掃描點雲資料蒐集。期許對古蹟保存工程提出更佳的解決方案。
本研究成果顯示：利用GNSS-RTK快速精密定位技術，在古宅銃櫃部分實施控制點補點作業，精度可達到允許的範圍內；實驗結果亦得知利用3D LiDAR地面控制測量，其特徵點經過專案坐標轉換為TWD97大地絕對坐標，其精度誤差均在公分級以下，可作為另種控制點雲坐標精度之參考。且經由修正後的3D LiDAR雷射掃描作業流程，不但快速便捷，古宅全區的點雲資料密度均在2mm的範圍內，符合作業精度要求。

By taking the historical site of the ancient house of Li Tengfang as an example, this study proposes an innovative thinking which is to use the combination of multi-satellite measurement technology (GNSS static observation, e-GNSS, and GNSS-RTK) to replace the traditional control measurement. The present work takes advantage of this new method of operation to analysis and research on the influence of the location accuracy and observation time of the historic site, and use this mode of operation to collect the laser scanning point cloud data for the entire area of the ancient house. It is expected that a better solution will be achieved for the restoration and preservation of Monument Maintenance Project.
The results of this research show that: Using GNSS-RTK rapidly precise positioning technology to implement rebuilt-point project of control points in the cabinet part of ancient house, accuracy can be achieved within the allowable range. The experimental results also reveals that the use of 3D LiDAR ground control measurement, feature points are converted into TWD97 coordinates through the standard of the procedure, the measurment accuracy can be achieved in the centimeter range, which can be used as a reference for another controlling point cloud of coordinate precision. Through the modified 3D LiDAR laser scanning procedure, the work is achieved in quickly and conveniently, and point cloud data of the whole house is achieved within the range of 2mm. Hence the technology fully meets job accuracy requirements.