立木樹冠植生情況為森林管理重要的參考指標，包含單株立木數量、立木位置、立木高度、材積與樹冠涵蓋範圍等，為獲取上述資訊，除藉由現地量測、航照立體對與雷達回波等資料獲得外，亦可由空載光達三維離散點雲萃取立木樹冠範圍與立木位置。由於森林區的特性，現地量測耗時費力，而航照影像與雷達回波資料於樹冠密集處不易辨識邊界位置。隨著空載雷射掃描儀性能的提升，於三維物空間萃取樹冠資訊具可行性，但現今光達資料多以網格式處理，萃取成果與網格大小與內插方式直接相關，且內插會造成高程資訊的損失。因此，本研究擬使用三維離散點偵測高程不連續處萃取樹冠邊界，進而獲得立木位置。由研究成果顯示，分析高程不連續處可有效獲取立木位置、立木高度與樹冠邊界。

The Biomass condition is important index in forest fields. The used information contain number of stems, stand position, tree height, timber volume, canopy cover, etc. In literature reviews, several studies extracted canopies using field surveying, aerial imagery, radar data, LIDAR data and so on. However, those manners are labor intensive and hard to identify crown edges in concentrated forest. Following the development of airborne laser scanning systems, this study proposes a scheme to detect forest canopies using high density point clouds. This study analyzes canopy profiles using empirical mode decomposition method to find the vertical discontinuities, i.e. crown edges. Finally, those adjacent detected boundaries are merged to describe complete canopy boundaries. The experimental results indicate that the proposed scheme has the capability to extract stand position, tree height, and crown edges.