以手持式雷射掃瞄系統結合UAV點雲影像進行桃花心木樹高量測之研究

Integration of hand-held mobile laser scanner and unmanned aerial vehicle to measure tree height

本研究探討以手持式移動雷射掃瞄系統(Hand-held Mobile Laser Scanner, HMLS)結合無人飛行載具(Unmanned Aerial Vehicle, UAV)點雲影像於屏東縣萬巒鄉台灣糖業股份有限公司所造林之桃花心木人工林，進行單木樹高量測。研究結果顯示，進行樹高測量，如果僅使用HMLS的點雲影像，其R2=0.65，RMSE=2.59 m，而整合HMLS與UAV時，如果配合飛行高度100 m、重疊度90%所產製之UAV點雲，能有效改善測量結果，此時R2=0.93，RMSE=0.88 m。HMLS便攜性和連續性掃瞄能夠克服地形與遮蔽視野之問題，再整合UAV無人飛行載具可取得完整之樹高資訊，其點雲資料具有三維空間資訊，可建立三維立體之數值模型、獲取準確之林木性態值，未來應可大範圍應用於森林調查，增加森林資源調查效率。

As information and technology advanced, forest investigation have gradually transformed from traditional tools to high technology methods. This study, focused at the plantation owned by Taiwan Sugar Cooperation in Wanluan Township, Pingtung County. We explored the integration of two different technologies, HMLS and UAV for use in forest inventory. The results revelaed that using HMLS alone provided a tree height correlation between HMLS and ground true data with R2=0.65 and RMSE=2.59 m. Howevr, ater incorporating UAV dense matching point cloud data, the correlation R2 increased to 0.93 and RMSE decreased to 0.88 m. The 1:1 linear regression also showed a significant positive correlation with no significant differences between the integration results and ground true data. From these findings, we validate our hypothesis about integrating HMLS and UAV into forest inventory process. We anticipate this integration method will prove beneficial for larger scale forest investigation.