Advances in the Derivation of Northeast Siberian Forest Metrics Using High-Resolution UAV-Based Photogrammetric Point Clouds
Abstract
:1. Introduction
2. Materials and Methods
2.1. Study Sites
2.1.1. Type I: Open, Larch Dominated Stands
2.1.2. Type II: Dense, Larch Dominated Stands
2.1.3. Type III: Dense, Mixed Tree Species Stands
2.2. Data Acquisition
2.3. Ground Classification and the Derivation of Digital Elevation Models
2.4. Individual Tree Detection and Crown Segmentation
2.5. Forest Stand Metric Derivation
2.6. Validation
3. Results
3.1. Point Cloud Reconstruction and Individual Tree Detection
3.2. Validation of Individual Tree Characteristics
3.3. Validation of the Stand Structure
3.4. Zonal Homogeneity Analysis
4. Discussion
4.1. Methodology Applicability for Various Forest Structures
4.2. Challenges in the Tree Segmentation Based on Canopy Height Models
5. Conclusions
Author Contributions
Funding
Acknowledgments
Conflicts of Interest
Appendix A
Appendix B
Site | No | W (cm) | H (cm) | Wdiff (cm) | Hdiff (cm) |
---|---|---|---|---|---|
EN18001 | 1 | 23.9 | 29.3 | −0.4 | 2.9 |
EN18001 | 2 | 21.2 | 31.2 | 1.5 | 0.2 |
EN18001 | 3 | 21.9 | 28.8 | −0.9 | 0.9 |
EN18003 | 1 | 22.4 | 30.4 | 0.7 | 1.4 |
EN18003 | 2 | 20.9 | 30.1 | 0.4 | −0.1 |
EN18003 | 3 | 23 | 30.4 | 0.7 | 2 |
EN18012 | 1 | 20.3 | 30.4 | 0.7 | −0.7 |
EN18012 | 2 | 21.5 | 30.4 | 0.7 | 0.5 |
EN18012 | 3 | 20.9 | 29.2 | −0.5 | −0.1 |
EN18014 | 1 | 22.5 | 30.3 | 0.6 | 1.5 |
EN18014 | 2 | 21.8 | 30.7 | 1 | 0.8 |
EN18014 | 3 | 22 | 30.9 | 1.2 | 1 |
EN18026 | 1 | 21.4 | 27.7 | −2 | 0.4 |
EN18026 | 2 | 21.1 | 30.3 | 0.6 | 0.1 |
EN18026 | 3 | 21.4 | 28.7 | −1 | 0.4 |
EN18027 | 1 | 21 | 29 | −0.7 | 0 |
EN18027 | 2 | 23.3 | 29.5 | −0.2 | 2.3 |
EN18027 | 3 | 21.2 | 31.2 | 1.5 | 0.2 |
EN18030 | 1 | 20.2 | 29.6 | −0.1 | −0.8 |
EN18030 | 2 | 20.2 | 29.7 | 0 | −0.8 |
EN18030 | 3 | 20.7 | 30.6 | 0.9 | −0.3 |
EN18070 | 1 | 22.6 | 30.7 | 1 | 1.6 |
EN18070 | 2 | 23.2 | 32.1 | 2.4 | 2.2 |
EN18070 | 3 | 21.2 | 29.7 | 0 | 0.2 |
EN18080 | 1 | 21.3 | 28.6 | −1.1 | 0.3 |
EN18080 | 2 | 22.6 | 30.4 | 0.7 | 1.6 |
EN18080 | 3 | 20.4 | 30.8 | 1.1 | −0.6 |
EN18083 | 1 | 22.2 | 31.2 | 1.5 | 1.2 |
EN18083 | 2 | 23 | 26 | −3.7 | 2 |
EN18083 | 3 | 22.4 | 32.5 | 2.8 | 1.4 |
MeanDiff | SD | ||||
0.51833333 | 1.15057836 |
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Sites | Rigidness | Cloth Resolution (m) | Classification Threshold (m) |
---|---|---|---|
EN18001/03/12 | 1 | 0.1 | 0.1 |
EN18014/26/27 | 1 | 0.2 | 0.1 |
EN18030/80 | 1 | 0.2 | 0.2 |
EN18070 | 2 | 0.2 | 0.3 |
EN18083 | 2 | 0.1 | 0.2 |
Sites | r (h) | Comments |
---|---|---|
EN18001/03/12/14/27 | 0.045 h + 0.8 | Small and widely spaced trees |
EN18070/26/80 | 0.020 h + 0.6 | Narrow and tall trees |
EN18083 | 0.020 h + 0.4 | Tall trees |
EN18030 | 0.035 h + 0.05 | Narrow, closely spaced, and small trees |
Sites | Type I | Type II | Type III | |||||||
---|---|---|---|---|---|---|---|---|---|---|
EN18001 | EN18003 | EN18012 | EN18014 | EN18026 | EN18027 | EN18030 | EN18070 | EN18080 | EN18083 | |
Latitude | 67.3927 | 67.3969 | 67.4021 | 67.3953 | 67.3961 | 67.3934 | 68.4055 | 63.0829 | 59.9771 | 59.9747 |
Longitude | 168.3468 | 168.3471 | 168.3781 | 168.3491 | 168.3543 | 168.3590 | 164.5327 | 117.9850 | 112.9613 | 113.0029 |
Plot area (m2) | 3673.84 | 4130.72 | 3895.52 | 4058.5 | 3549.85 | 3841.82 | 3769.85 | 9474.81 | 3782.64 | 2943.26 |
Mean slope (°) | 12.5 | 23.01 | 12.07 | 12 | 14.93 | 15.66 | 15.13 | 13.89 | 16.02 | 16.98 |
Mean aspect (°) | 163.22 | 164.96 | 184.41 | 128.24 | 154.25 | 170.48 | 167.97 | 179.63 | 182.8 | 212.09 |
Total detected | 181 | 146 | 259 | 240 | 153 | 297 | 1733 | 759 | 681 | 270 |
Tree density (n/h) | 492.67 | 353.45 | 664.87 | 591.35 | 431 | 773.07 | 4597 | 801.07 | 1800.33 | 917.35 |
Cover | 0.21 | 0.23 | 0.19 | 0.16 | 0.22 | 0.26 | 0.53 | 0.4 | 0.3 | 0.38 |
Mean height (m) | 6.58 | 6.48 | 4.95 | 3.99 | 6.13 | 6.86 | 4.82 | 14.76 | 5.26 | 17.56 |
SD height | 3.27 | 3.11 | 2.71 | 2.63 | 3.41 | 3.28 | 1.59 | 5.4 | 4.46 | 8.39 |
Mean crown area (m2) | 4.24 | 6.42 | 2.83 | 2.77 | 5.17 | 3.35 | 1.15 | 4.98 | 1.68 | 4.18 |
SD crown area | 3.84 | 5.83 | 2.43 | 2.85 | 4.18 | 2.75 | 0.74 | 4.26 | 2.09 | 3.98 |
Mean crown diameter (m) | 2.31 | 2.95 | 1.91 | 1.81 | 2.67 | 2.16 | 1.31 | 2.74 | 1.44 | 2.47 |
SD mean crown diameter | 1.33 | 1.44 | 0.94 | 1.1 | 1.2 | 0.99 | 0.45 | 1.23 | 0.92 | 1.29 |
Site | Type I | Type II | Type III | |||||||
---|---|---|---|---|---|---|---|---|---|---|
EN18001 | EN18003 | EN18012 | EN18014 | EN18026 | EN18027 | EN18030 | EN18070 | EN18080 | EN18083 | |
ND/NO | 7/10 | 10/11 | 9/11 | 33/68 | 11/15 | 8/10 | 12/12 | 11/20 | 23/30 | 23/32 |
Percentage ND/NO | 70 | 91 | 82 | 49 | 73 | 80 | 100 | 55 | 77 | 72 |
Mean H | 5.1 | 5.25 | 6.07 | 4.51 | 7.37 | 5.76 | 6.39 | 11.1 | 7.53 | 14.12 |
SD H | 3.52 | 3.04 | 3.21 | 4.15 | 4.14 | 2.7 | 3.21 | 7.31 | 6.45 | 8.73 |
Smallest detected | 3.75 | 1.8 | 1.65 | 2.2 | 7 | 4.1 | 1.95 | 4.5 | 0.96 | 2.6 |
Tallest un-detected | 2.05 | 1.75 | 1.23 | 8 | 2.9 | 1.7 | - | 9 | 2.5 | 12 |
H R2 | 0.67 | 0.76 | 0.63 | 0.86 | 0.64 | 0.83 | 0.87 | 0.82 | 0.96 | 0.67 |
H RMSE | 1.56 | 1.29 | 1.11 | 1 | 1.22 | 0.63 | 0.62 | 2 | 1.08 | 3.73 |
H RMSE% | 28.32 | 21.77 | 18.58 | 3.52 | 22.52 | 16.06 | 9.55 | 26.17 | 7.3 | 28.41 |
Mean CD | 2.1 | 2.42 | 2.42 | 1.99 | 3.1 | 2.56 | 1.51 | 2.95 | 1.54 | 2.42 |
SD CD | 1.28 | 1.93 | 1.43 | 1.77 | 1.89 | 1.51 | 0.95 | 2.09 | 1.35 | 1.43 |
CD R2 | 0.94 | 0.81 | 0.13 | 0.62 | 0.64 | 0.22 | 0.32 | 0.26 | 0.34 | 0.13 |
CD RMSE | 0.27 | 0.78 | 0.99 | 0.68 | 0.5 | 0.55 | 0.37 | 1.19 | 0.73 | 0.99 |
CD RMSE% | 10.63 | 26.65 | 28.73 | 23.54 | 15.81 | 21.89 | 22.63 | 33.34 | 40.82 | 28.73 |
Over-Segmentation (Commission Errors) | Under-Segmentation (Omission Errors) | Height Underestimation | |
---|---|---|---|
Narrow search | - Occasional wide or very flat crowns - Occasional fragmented crowns - Occasional complete crowns - Leaning trees | - | - |
Wide search | - | - Occasional narrow crowns - Partially overlapping trees | - |
Low min. height | - Misclassified ground vegetation - Elevated horizontal dead wood | - | - |
High min. height | - | - Small trees will not be detected | - |
Strong smoothing | - | - Very closely spaced tree tops - Partially overlapping trees - Small, narrow trees will not be detected | - |
Weak smoothing | - Side branches create multiple local maxima - Occasional fragmented crowns - Leaning trees with multiple local maxima | - | - |
Always | - | - Overlapping crowns (subordinated trees) | - Trees with thin, leafless tops - Leaning trees - Small, shrub like trees |
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Brieger, F.; Herzschuh, U.; Pestryakova, L.A.; Bookhagen, B.; Zakharov, E.S.; Kruse, S. Advances in the Derivation of Northeast Siberian Forest Metrics Using High-Resolution UAV-Based Photogrammetric Point Clouds. Remote Sens. 2019, 11, 1447. https://doi.org/10.3390/rs11121447
Brieger F, Herzschuh U, Pestryakova LA, Bookhagen B, Zakharov ES, Kruse S. Advances in the Derivation of Northeast Siberian Forest Metrics Using High-Resolution UAV-Based Photogrammetric Point Clouds. Remote Sensing. 2019; 11(12):1447. https://doi.org/10.3390/rs11121447
Chicago/Turabian StyleBrieger, Frederic, Ulrike Herzschuh, Luidmila A. Pestryakova, Bodo Bookhagen, Evgenii S. Zakharov, and Stefan Kruse. 2019. "Advances in the Derivation of Northeast Siberian Forest Metrics Using High-Resolution UAV-Based Photogrammetric Point Clouds" Remote Sensing 11, no. 12: 1447. https://doi.org/10.3390/rs11121447
APA StyleBrieger, F., Herzschuh, U., Pestryakova, L. A., Bookhagen, B., Zakharov, E. S., & Kruse, S. (2019). Advances in the Derivation of Northeast Siberian Forest Metrics Using High-Resolution UAV-Based Photogrammetric Point Clouds. Remote Sensing, 11(12), 1447. https://doi.org/10.3390/rs11121447