曹 忠,巩奕成,冯仲科,于东海,祁 曼.电子经纬仪测量立木材积误差分析[J].农业机械学报,2015,46(1):292-298.
Cao Zhong,Gong Yicheng,Feng Zhongke,Yu Donghai,Qi Man.Error Analysis on Standing Tree Volume Measurement by Using Electronic Theodolites[J].Transactions of the Chinese Society for Agricultural Machinery,2015,46(1):292-298.
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电子经纬仪测量立木材积误差分析   [下载全文]
Error Analysis on Standing Tree Volume Measurement by Using Electronic Theodolites   [Download Pdf][in English]
投稿时间:2014-09-25  
DOI:10.6041/j.issn.1000-1298.2015.01.041
中文关键词:  电子经纬仪 立木材积 树高 误差传播定律
基金项目:国家自然科学基金资助项目(41371001)
作者单位
曹 忠 北京林业大学 
巩奕成 北京工业大学
俄亥俄州立大学 
冯仲科 北京林业大学 
于东海 北京林业大学 
祁 曼 北京林业大学 
中文摘要:以北京市杨树立木材积实测数据作为检核真值,按误差传播定律对电子经纬仪测树误差进行分析,并依据我国电子经纬仪精度划分的Ⅰ(DJ-1)、Ⅱ(DJ-2)、Ⅲ(DJ-6)和Ⅳ(DJ-15)4个等级,计算该方法测量树高和材积的误差和2倍中误差的极限误差,分析不同精度电子经纬仪测树的差异性和适应性。结果表明:由于误差的传播和累积,同一精度电子经纬仪测量材积的误差大于树高。同一精度电子经纬仪测量不同规格样木时,误差会随着树木大小的变化而略有差异。随着电子经纬仪测角标准偏差的变大,测树的误差也会变大。电子经纬仪标准偏差为±0.5″时,测量树高和材积的中误差分别为±6.5500×10-2m和±1.474×10-3m3,相对误差分别为0.44%和0.73%。电子经纬仪标准偏差为±15.0″时,测量树高和材积的中误差分别为±8.9275×10-2m和±4.385×10-3m3,相对误差分别为0.60%和2.14%。说明我国现有的Ⅰ~Ⅳ级电子经纬仪测树结果均符合相对误差不超过3%~5%的精度要求,可以满足不同林业调查工作的需要。
Cao Zhong  Gong Yicheng  Feng Zhongke  Yu Donghai  Qi Man
Beijing Forestry University,Beijing University of Technology;Ohio State University,Beijing Forestry University,Beijing Forestry University and Beijing Forestry University
Key Words:Electronic theodolite Standing tree volume Tree height Laws of error propagation
Abstract:In traditional forestry works, the compilation of volume tables by cutting down trees and using analytic timber volume estimations is faced of problems such as large destruction, high costs and low efficiency. Therefore, an estimation method was proposed. First, diameter at breast height and ground diameter were manually measured. Then, the horizontal angles and zenith distances at corresponding trunk positions of live standing trees were measured by using the approximate division of analytic timber based on an electronic theodolite. Finally, the timber volume was estimated by simulating mean sectional division volume as per summation of conical frustum. The measured data of standing timber volumes from poplar in Beijing were used as true data for examination. The errors of timber measurement from electronic theodolites were theoretically analyzed according to error propagation laws. Based on the four grades of electronic theodolite precision classification in China: Ⅰ(DJ-1), Ⅱ(DJ-2), Ⅲ(DJ-6) and Ⅳ(DJ-15), the errors and the limit errors of root mean square error (RMSE) during measurements of tree height and timber volume were computed. Moreover, the differences and applicability of electronic theodolites with different precision levels were analyzed. The results showed that because of error propagation and accumulation, the errors of timber volumes measured by electronic theodolites with the same precision were larger than the errors of tree height. When timbers with different sizes were measured by electronic theodolites of the same precision level, the errors slightly changed along with the size of timbers. With the increased standard deviation in angle measurements by electronic theodolites, the errors in forest measurement also increased. When the standard deviation of electronic theodolites was ±0.5″, the RMSEs in measurements of tree height and timber volume were ±6.5500×10-2m and ±1.474×10-3m3, respectively, while the relative errors were 0.44% and 0.73%, respectively. When the standard deviation of electronic theodolites was ±15.0″, the RMSEs in measurements of tree height and timber volume were ±8.9275×10-2m and ±4.385×10-3m3, respectively, while the relative errors were 0.60% and 2.14%, respectively. Therefore, the existing Ⅰ~Ⅳ electronic theodolites applied into tree measurements all conform to the precision requirement that relative errors do not exceed 3%~5%, and satisfy the requirements of different forestry works.

Transactions of the Chinese Society for Agriculture Machinery (CSAM), in charged of China Association for Science and Technology (CAST), sponsored by CSAM and Chinese Academy of Agricultural Mechanization Science(CAAMS), started publication in 1957. It is the earliest interdisciplinary journal in Chinese which combines agricultural and engineering. It always closely grasps the development direction of agriculture engineering disciplines and the published papers represent the highest academic level of agriculture engineering in China. Currently, nearly 8,000 papers have been already published. There are around 3,000 papers contributed to the journal each year, but only around 600 of them will be accepted. Transactions of CSAM focuses on a wide range of agricultural machinery, irrigation, electronics, robotics, agro-products engineering, biological energy, agricultural structures and environment and more. Subjects in Transactions of the CSAM have been embodied by many internationally well-known index systems, such as: EI Compendex, CA, CSA, etc.

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