基于数字摄影测量的森林蓄积量估算

Forest Volume Estimation Based on Digital Photogrammetry

利用收集到的东北林业大学哈尔滨市城市林业基地的16张航片和相应的外方位元素,建立了一个测区,通过模型的内定向、相对定向和绝对定向构建了测区的立体像对模型,选择了有代表性的8个小班。在立体像对模型的基础之上,利用专业的数字摄影测量平台估测了8个小班的蓄积量。同时用样地法实地测量了8个小班的蓄积量,并将实地估算结果与数字摄影测量估算结果进行了对比分析。分析发现:两组数据的差异不显著,基于数字摄影测量的蓄积量估算平均精度为85.3%,最高精度为98.7%。研究结论说明,使用数字摄影测量方法估测其蓄积量,其精度比较高,该方法可以在一定条件下接近或满足森林资源调查的精度要求。

A survey area was built up based on sixteen aerial photos of the Experimental Forest Farm of Northeast Forestry University and their exterior orientation elements. The models of stereopair were established through interior orientation,relative orientation,and absolute orientation. Volumes of eight typical subcompartments were estimated by the platform of professional digital photogrammetry system based on the stereopair models. In the same time,the volumes of the eight subcompartments were measured by the investigation method of sample plot. Then the field data of volume were compared with the volume estimated by the photogrammetric results. Results show that the difference in volume of the two groups is not remarkable. The average precision for forest volume estimation based on digital photogrammetry was 85.3%,and the highest precision was 98.7%. Digital photogrammetry exhibits a higher precision for forest volume estimation,and it can be applied to the investigation of forest resources under certain conditions.