基于VirtuoZo系统对林木冠幅信息的提取

Extraction of Tree's Crown Diameter Information Based on VirtuoZo System

针对目前林木冠幅信息人工测量高误差低效率的现状,本文基于1∶10 000的数字航空相片影像,采用专业的数字摄影测量平台VirtuoZo提取了林木冠幅信息。选取凉水国家级自然保护区17林班18小班内第32号固定样地为测图区,通过立体模型的内定向、相对定向和绝对定向构建测区的立体像对,并在立体像对上量测了样地内各林木的东西和南北冠幅。结果表明:林木冠幅的数字摄影测量的相关系数均大于0.85,具有较好的正相关性。因此应用全数字测量系统VirtuoZo提取冠幅因子具有可行性,能够减少外业工作量,但测量精度受到航摄参数、环境因素和判读员经验等因素影响。

Aiming at the status of high error and low efficiency existing in manual measurement of tree＇s crown diameter information, the professional digital photogrammetric platform VirtuoZo was applied to extract tree＇ s crown diameter information based on 1 ： 10000 digital aerial photos. The No. 32 sample plot in sub - compartment 18 of the compartment 17 in Liangshui National Nature Reserve was selected as mapping area. The stereo pair of measured area was established based on the interior orientation, relative orientation and absolute orientation of three - dimensional model, and the crown diameter of each tree in the plot was measured. The results showed that the correlation coefficients of tree crown diameter with digital photogrammetry were larger than 0. 85, appearing good positive correlation. Therefore, it is feasible to measure crown diameter using digital photogrammetry system VirtuoZo in order to reduce the field workload. However, the measurement precision is also influenced by aerial photographic parameters, environmental factors, as well as experiences of interpreters.