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New Hybrid Algorithms for Estimating Tree Stem Diameters at Breast Height Using a Two Dimensional Terrestrial Laser Scanner.

Kong J, Ding X, Liu J, Yan L, Wang J - Sensors (Basel) (2015)

Bottom Line: In this paper, a new algorithm to improve the accuracy of estimating diameter at breast height (DBH) for tree trunks in forest areas is proposed.Compared with previous works, this proposed method improves the accuracy of diameter estimation of trees significantly and effectively reduces the calculation time.Moreover, the experimental results indicate that this method is stable and suitable for the most challenging conditions, which has practical significance in improving the operating efficiency of forest harvester and reducing the risk of causing accidents.

View Article: PubMed Central - PubMed

Affiliation: School of Technology, Beijing Forestry University, Beijing 100083, China. kongjianlei_slgc@163.com.

ABSTRACT
In this paper, a new algorithm to improve the accuracy of estimating diameter at breast height (DBH) for tree trunks in forest areas is proposed. First, the information is collected by a two-dimensional terrestrial laser scanner (2DTLS), which emits laser pulses to generate a point cloud. After extraction and filtration, the laser point clusters of the trunks are obtained, which are optimized by an arithmetic means method. Then, an algebraic circle fitting algorithm in polar form is non-linearly optimized by the Levenberg-Marquardt method to form a new hybrid algorithm, which is used to acquire the diameters and positions of the trees. Compared with previous works, this proposed method improves the accuracy of diameter estimation of trees significantly and effectively reduces the calculation time. Moreover, the experimental results indicate that this method is stable and suitable for the most challenging conditions, which has practical significance in improving the operating efficiency of forest harvester and reducing the risk of causing accidents.

No MeSH data available.


The raw laser data scanning result.
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sensors-15-15661-f002: The raw laser data scanning result.

Mentions: To measure the DBH of living-trees in a real forestry environment, outdoor experiments were carried out in birch forest located in the Peking Olympic Park. In our experiments, the 2D laser scanner is fixed on a tripod with telescopic legs as seen in Figure 1. The laser scanner sends and receives the laser beams reflected by tree trunks or other objects to form a fan-shaped scan, which is represents the surrounding area as shown in Figure 2. Here the height of the scanning plane is equal to about 1.3 m from the ground, as measured by a tape. This leads to better results because the understory and other uninteresting objects lie below the scanning plane in this experiment. The equipment was placed at different 15 places and 60 trees were nearly totally scanned. In order to completely demonstrate the procedure of laser data optimization and DBH estimation, only the raw laser clouds at the position with the eight silver birches are presented in the experiment results using real data. Those targets are applied to reveal the DBH estimation error fitted by the hybrid algorithm in contrast with the manual work. The actual laser data is shown in the Figure 2, and the images obtained by the thermal camera are seen in Figure 3. However, all 60 targets measured are used to confirm the excellence of the proposed method compared with other algorithms in the comparison part.


New Hybrid Algorithms for Estimating Tree Stem Diameters at Breast Height Using a Two Dimensional Terrestrial Laser Scanner.

Kong J, Ding X, Liu J, Yan L, Wang J - Sensors (Basel) (2015)

The raw laser data scanning result.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4541849&req=5

sensors-15-15661-f002: The raw laser data scanning result.
Mentions: To measure the DBH of living-trees in a real forestry environment, outdoor experiments were carried out in birch forest located in the Peking Olympic Park. In our experiments, the 2D laser scanner is fixed on a tripod with telescopic legs as seen in Figure 1. The laser scanner sends and receives the laser beams reflected by tree trunks or other objects to form a fan-shaped scan, which is represents the surrounding area as shown in Figure 2. Here the height of the scanning plane is equal to about 1.3 m from the ground, as measured by a tape. This leads to better results because the understory and other uninteresting objects lie below the scanning plane in this experiment. The equipment was placed at different 15 places and 60 trees were nearly totally scanned. In order to completely demonstrate the procedure of laser data optimization and DBH estimation, only the raw laser clouds at the position with the eight silver birches are presented in the experiment results using real data. Those targets are applied to reveal the DBH estimation error fitted by the hybrid algorithm in contrast with the manual work. The actual laser data is shown in the Figure 2, and the images obtained by the thermal camera are seen in Figure 3. However, all 60 targets measured are used to confirm the excellence of the proposed method compared with other algorithms in the comparison part.

Bottom Line: In this paper, a new algorithm to improve the accuracy of estimating diameter at breast height (DBH) for tree trunks in forest areas is proposed.Compared with previous works, this proposed method improves the accuracy of diameter estimation of trees significantly and effectively reduces the calculation time.Moreover, the experimental results indicate that this method is stable and suitable for the most challenging conditions, which has practical significance in improving the operating efficiency of forest harvester and reducing the risk of causing accidents.

View Article: PubMed Central - PubMed

Affiliation: School of Technology, Beijing Forestry University, Beijing 100083, China. kongjianlei_slgc@163.com.

ABSTRACT
In this paper, a new algorithm to improve the accuracy of estimating diameter at breast height (DBH) for tree trunks in forest areas is proposed. First, the information is collected by a two-dimensional terrestrial laser scanner (2DTLS), which emits laser pulses to generate a point cloud. After extraction and filtration, the laser point clusters of the trunks are obtained, which are optimized by an arithmetic means method. Then, an algebraic circle fitting algorithm in polar form is non-linearly optimized by the Levenberg-Marquardt method to form a new hybrid algorithm, which is used to acquire the diameters and positions of the trees. Compared with previous works, this proposed method improves the accuracy of diameter estimation of trees significantly and effectively reduces the calculation time. Moreover, the experimental results indicate that this method is stable and suitable for the most challenging conditions, which has practical significance in improving the operating efficiency of forest harvester and reducing the risk of causing accidents.

No MeSH data available.