手杖式测树仪立木树高量测研究

目的]树高是森林经营决策中最重要的一个参量,常用于估计森林生长、年龄、材积、生物量和碳储量等立木参数,其精度对立木质量的评价及森林生长的预测分析影响重大.为解决传统的树高量测仪器移动不便,测量周期长,人力耗损大等问题.方法]以近景摄影测量为基础,构建了一种以登山杖绑定安卓智能手机为测量平台的便携、快捷的树高测量装备...

Study on tree height measurement based on stick-type tree measuring instrument

【Objective】Tree height is one of the most important parameters in forest management decision-making.It is often used to estimate tree parameters such as forest growth,age,volume,biomass and carbon storage.Its accuracy has a significant impact on the evaluation of tree quality and the prediction and analysis of forest growth.In order to solve the problems such as inconvenient moving,long measuring period and large manpower consumption of traditional tree height measuring instrument.【Method】On the basis of close range photogrammetry,this study constructed a portable and fast tree height measurement equipment based on the combination of climbing stick and Android smart phone.According to whether there is slope in the growing environment and whether there is dip angle in the shooting,the measurement model of tree height is established.Under the environment of mobile phone,the software app for measuring the height of tree is developed.It uses up and down split screen technology,mobile phone imaging system and coordinate system conversion to associate the screen and tree,so as to automatically calculate the depth information of tree.Combined with the powerful performance of the direction sensor inside the mobile phone,the tree height estimation can be obtained in real time by single station operation.In Hongshimen village,Pinggu district,Beijing,307 trees with different slopes were selected as the research objects.The equipment was used to measure them at the up slope and down slope respectively,and the results were compared with the average values obtained by the total station.【Result】The average absolute error of tree height estimation is 0.21 m,the average relative error is 2.11%and the overall accuracy is 97.89%.When it is in the downhill position,the average absolute error of tree height is 0.11 m,the average relative error is 1.16%,and the accuracy of tree height is 98.84%.When it is in the uphill position,the average absolute error of tree height estimation is 0.32 m,the average relative error is 3.07%,and the accuracy of tree height reaches 96.93%.When the tilt angle of smart phone is large,the accuracy reaches 95.19%,and when the tilt angle of smart phone is small,the accuracy reaches 99.03%.This shows that the smaller the tilt angle produced by stick-type tree measuring instrument is,the higher the accuracy is.When measuring the same tree,the accuracy of downhill position observation is better than that of uphill position.【Conclusion】The research and development of this equipment can meet the measurement accuracy requirements of the national forest resources continuous inventory,and the equipment has low cost,strong flexibility,does not rely on other equipment to obtain depth information,is convenient to carry,and has high utilization value.It can be used as the height measurement equipment of forest resources investigation tree in the future.