近年來因微機電系統(Micro-electromechanical Systems - MEMS)的演進迅速，提升無人飛行載具UAV (Unmanned Aerial Vehicle)自動導航系統的可靠度和性能，使得UAV操控可以完全自動化，提升航拍作業時的安全性，又因UAV有較佳的機動性和可在低空30-50公尺執行任務，以取得高解析度的航拍影像，因此平時可進行長期的環境變遷監測；災時可快速取得影像資料，以做為決策分析等應用。但傳統使用UAV進行正射影像產製，必須透過地面控制測量、空中三角測量與立體製圖等方式，才可以取得正射影像與地形資訊，無法滿足災害發生時需快速取得空間資料之需求，因此如何透過UAV所拍攝的影像資訊快速產製正射影像與地形資訊為本研究之重點。本研究將以Pix4Dmapper為先進技術軟體，探討以UAV航拍取像後，透過先進技術取得正射影像與地形資料之可行性。結果顯示，UAV拍攝所得影像透過Pix4Dmapper進行影像匹配三維點生成地表模型，快速生產正射影像，並可以不需經由人工介入的空中三角測量步驟回推內、外方位參數。並以苗栗後龍溪測區為例，在涵蓋範圍4平方公里，影像數量354張，在自動化的作業流程下，可在5小時內取得相關空間資料，經檢核後，正射影像之平面精度均方根誤差30 cm內。

It is the rapidly developing and evolution of micro-electromechanical systems (MEMS) in the past years and it have been improved for the reliability and performance of the automatic navigation and operation system of UAV (Unmanned Aerial Vehicle), hence UAV can be fully automated and improved the security during aerial photo capturing. Due to UAV has better mobility and can perform tasks at low altitude in 30m to 50m to obtain high-resolution aerial image, so it can be using in long-term environmental change monitoring in normal ; but it can quickly obtain the aerial image data in disaster to analyze and make the decision and other applications. However, the traditional orthoimage process to produce images captured by UAV, it has to implement ground-based measurements, aerial triangulation, and stereoscopic mapping are required to obtain orthophoto and terrain information, but it can not meet the need for rapid acquisition of spatial data when a disaster occurs. How to produce orthophoto and terrain information by UAV is the focus of this study. The study focus on optimizing the process and on reducing time-consumption to acquiring orthophotos and the DSM from UAVs’ aerial image by using Pix4Dmapper. The Pix4Dmapper could automatically process orthophotos and the DSM purely using aerial image captured by UAVs. The Houlong River, Miaoli, Taiwan case is used in the study. The Houlong River covers an area about 4 sq. km, and the analysis of aerial images of the River are 354 images. The automatic process workflow of acquiring orthophotos and the DSM from the aerial images by the Pix4Dmapper is within 5 hours. And the accuracy achieve 30 cm RMS error.

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