不同方法提取无人机影像树冠信息效果分析

以无人机航空拍摄的影像为数据源，采用目视解译和面向对象法提取胡杨、柽柳树冠信息，获得树木冠幅及林分郁闭度.结果表明，单木冠幅、林分冠幅、样地郁闭度的实测值、面向对象法估测值和目视解译法估测值无显著差异（P＞0．05），表明面向对象与目视解译法都可有效获取单木冠幅、林分冠幅和样地郁闭度信息；面向对象法与目视解译法估测精度无显著差异（P＞0．05），表明这两种方法获取森林单木冠幅、林分冠幅、样地郁闭度参数效果相当.但基于无人机航拍数据的面向对象树冠提取，能克服人机对话目视解译速度慢、误差大小因人而异的弊端，具有进行大面积林分调查因子定量提取的优势.

Analysis on Effects of Tree Crown Information from Unmanned Aerial Vehicle Image Extraction by Different Methods

The present study was set to chose visual interpretation method and obj ectGoriented method to extract tree crown information of populus diversiforia and tamarix chiness and to obtain access crown diG ameters and forest stand canopy density by using Unmanned Aerial Vehicle （UAV）image as data sourse. The result showed that there were no significant differences among measured values of individual tree crown,closure density of sample prots,forest stand canopy density,estimation values of obj ectGorientd method,visual interpretation method （P ＆gt;0.05）,indicating that the information of closue density of samG ple prots,individual tree crown,forest stand canopy density can be effectively obtained by the obj ect GorienG ted method and visual interpretation method;there were no significant differences between obj ectGoriented method and visural interpretation method （P ＆gt;0.05）,indicating that the parameter effects,by which forG est individual tree crown,forest stand canopy density and closure density of sample plots were obtained, had little difference between themselves.But the crown extraction method of obj ectGoriented can overcome the drawbacks of manGcomputer interaction visual interpretation,which is slow and error varies from perG son to person.The method has the advantages of quantitative extraction of a large area stand survey factor.