Holmgren, Johan
(2003).
Estimation of forest variables using airborne laser scanning.
Diss. (sammanfattning/summary)
Umeå :
Sveriges lantbruksuniv.,
Acta Universitatis Agriculturae Sueciae. Silvestria, 1401-6230
; 278
ISBN 91-576-6512-5
[Doctoral thesis]
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PDF
1MB |
Abstract
Airborne laser scanning can provide three-dimensional measurements of the forest canopy with high efficiency and precision. There are presently a large number of airborne laser scanning instruments in operation. The aims of the studies reported in this thesis were, to develop and validate methods for estimation of forest variables using laser data, and to investigate the influence of laser system parameters on the estimates. All studies were carried out in hemi-boreal forest at a test area in southwestern Sweden (lat. 58°30’N, long. 13°40’ E). Forest variables were estimated using regression models. On plot level, the Root Mean Square Error (RMSE) for mean tree height estimations ranged between 6% and 11% of the average value for different datasets and methods. The RMSE for stem volume estimations ranged between 19% and 26% of the average value for different datasets and methods. On stand level (area 0.64 ha), the RMSE was 3% and 11% of the average value for mean tree height and stem volume estimations, respectively. A simulation model was used to investigate the effect of different scanning angles on laser measurement of tree height and canopy closure. The effect of different scanning angles was different within different simulated forest types, e.g., different tree species. High resolution laser data were used for detection of individual trees. In total, 71% of the field measurements were detected representing 91% of the total stem volume. Height and crown diameter of the detected trees could be estimated with a RMSE of 0.63 m and 0.61 m, respectively. The magnitude of the height estimation errors was similar to what is usually achieved using field inventory. Using different laser footprint diameters (0.26 to 3.68 m) gave similar estimation accuracies. The tree species Norway spruce (Picea abies L. Karst.) and Scots pine (Pinus sylvestris L.) were discriminated at individual tree level with an accuracy of 95%. The results in this thesis show that airborne laser scanners are useful as forest inventory tools. Forest variables can be estimated on tree level, plot level and stand level with similar accuracies as traditional field inventories.
Authors/Creators: | Holmgren, Johan | ||||||||||||
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Title: | Estimation of forest variables using airborne laser scanning | ||||||||||||
Series/Journal: | Acta Universitatis Agriculturae Sueciae. Silvestria (1401-6230) | ||||||||||||
Year of publishing : | August 2003 | ||||||||||||
Volume: | 278 | ||||||||||||
Number of Pages: | 43 | ||||||||||||
Papers/manuscripts: |
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Place of Publication: | Umeå | ||||||||||||
Publisher: | Dept. of Forest Resource Management and Geomatics, Swedish University of Agricultural Sciences | ||||||||||||
ISBN for printed version: | 91-576-6512-5 | ||||||||||||
ISSN: | 1401-6230 | ||||||||||||
Language: | English | ||||||||||||
Publication Type: | Doctoral thesis | ||||||||||||
Full Text Status: | Public | ||||||||||||
Agris subject categories.: | K Forestry > K10 Forestry production U Auxiliary disciplines > U40 Surveying methods | ||||||||||||
Subjects: | Not in use, please see Agris categories | ||||||||||||
Agrovoc terms: | forest stands, canopy, height, classification, identification, crown, forest inventories, simulation models, laser radiation | ||||||||||||
Keywords: | LIDAR, tree detection, species classification, scan angle, tree height, crown closure, laser measurement density | ||||||||||||
URN:NBN: | urn:nbn:se:slu:epsilon-67 | ||||||||||||
Permanent URL: | http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-67 | ||||||||||||
ID Code: | 334 | ||||||||||||
Faculty: | S - Faculty of Forest Sciences | ||||||||||||
Department: | (S) > Dept. of Forest Resource Management (NL, NJ) > Dept. of Forest Resource Management | ||||||||||||
Deposited By: | Staff Epsilon | ||||||||||||
Deposited On: | 25 Aug 2003 00:00 | ||||||||||||
Metadata Last Modified: | 02 Dec 2014 10:03 |
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