XXII ISPRS Congress 2012: Technical Commission VIII

Shortis, M.; Shimoda, H.; Cho, K.

Bibliographic data

Multivolume work

Persistent identifier:: 1663813779

Title:: XXII ISPRS Congress 2012

Sub title:: Melbourne, Australia, 25 August-1 September 2012

Year of publication:: 2013

Place of publication:: Red Hook, NY

Publisher of the original:: Curran Associates, Inc.

Identifier (digital):: 1663813779

Language:: English

Additional Notes:: Kongress-Thema: Imaging a sustainable future

Corporations:: International Society for Photogrammetry and Remote Sensing, Congress, 22., 2012, Melbourne; International Society for Photogrammetry and Remote Sensing

Adapter:: International Society for Photogrammetry and Remote Sensing, Congress, 22., 2012, Melbourne; International Society for Photogrammetry and Remote Sensing

Founder of work:: International Society for Photogrammetry and Remote Sensing, Congress, 22., 2012, Melbourne; International Society for Photogrammetry and Remote Sensing

Other corporate:: International Society for Photogrammetry and Remote Sensing, Congress, 22., 2012, Melbourne; International Society for Photogrammetry and Remote Sensing

Document type:: Multivolume work

Volume

Persistent identifier:: 1663822514

Title:: Technical Commission VIII

Scope:: 590 Seiten

Year of publication:: 2014

Place of publication:: Red Hook, NY

Publisher of the original:: Curran Associates, Inc.

Identifier (digital):: 1663822514

Illustration:: Illustrationen, Diagramme

Signature of the source:: ZS 312(39,B8)

Language:: English

Additional Notes:: Erscheinungsdatum des Originals ist ermittelt.; Literaturangaben

Usage licence:: Attribution 4.0 International (CC BY 4.0)

Editor:: Shortis, M.; Shimoda, H.; Cho, K.

Corporations:: International Society for Photogrammetry and Remote Sensing, Congress, 22., 2012, Melbourne; International Society for Photogrammetry and Remote Sensing

Adapter:: International Society for Photogrammetry and Remote Sensing, Congress, 22., 2012, Melbourne; International Society for Photogrammetry and Remote Sensing

Founder of work:: International Society for Photogrammetry and Remote Sensing, Congress, 22., 2012, Melbourne; International Society for Photogrammetry and Remote Sensing

Other corporate:: International Society for Photogrammetry and Remote Sensing, Congress, 22., 2012, Melbourne; International Society for Photogrammetry and Remote Sensing

Publisher of the digital copy:: Technische Informationsbibliothek Hannover

Place of publication of the digital copy:: Hannover

Year of publication of the original:: 2019

Document type:: Volume

Collection:: Earth sciences

Chapter

Title:: [VIII/7: Forestry]

Document type:: Multivolume work

Structure type:: Chapter

Chapter

Title:: DEVELOPMENT OF PHOTOGRAMMETRY SYSTEM FOR GRASPING FOREST RESOURCES INFORMATION Y. Uramoto, L. Zhu, K. Tachibana, H. Shimamura, N. Ogaya

Document type:: Multivolume work

Structure type:: Chapter

XXIX-B8, 2012 | matrix ection center 1 ground coordinate stereo image for 3D orporated. With this very less knowledge use this system. ivigation seamlessly th) is also integrated e of the real world ncludes the map, or te project which will ISers position with function has been olume directly from ulation is a function number of trees per of timber volume volume DY areas, UltraCamX red with GSD of performed during ess of the forest. region Japan. The containing planted ly consisting oak, can also be visited International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B8, 2012 XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia htp;//fddb.ffpri-108.affrc.go.jp/en/03 ogawa/index.html The area used for measuring the tree heights for this experimental study is shown Figure 3. The area contains conifers trees, deciduous trees, and the ground surface (fields, roads). 33 Outline of the experimental study The tree height, used in the calculation of timber volume, in the system is calculated by subtracting the elevation of the crown top and the ground level. Hence, the accuracy of the measurement depends on the accurate measurement of the crown top and the ground surface. The top of the tree crown is measured directly on the system by putting the cursor at the top of the tree and by adjusting the tree height within the stereo pair. To measure tree height, the ground elevation under the tree canopy obtained from Triangulated Irregular Network (TIN) constructed from the total station ground survey points was used. The difference in elevation between the tree height measured and the ground height under the tree canopy measured from the TIN gave the tree height. To evaluate the accuracy of the tree height measurement, the measurement of the elevation of the top of the tree crown obtained by the automatic stereo matching between the image pair was used as the base data for this experiment. The ID numbers in Figure. 3 are the measurement points of confiers trees, decidious trees and the ground points. For the accuracy evaluation of ground height measured by Morittai, the ground elevation measured by Morittai was compared against ground elevation constructed from LiDAR data. 3.4 Result and Discussion As a test of the system, two persons were assigned to measure the top of the conifer trees, deciduous trees and the ground elevation. One of the person employed for the test was a beginner with no prior experience in forestry and photo interpretation. However, the other person who took part in the experiment had a lot of experience in photo interpretation but no knowledge about forestry. The accuracy of the height measurement in the Morritai by the participants is shown in Figure 4. In the figure, ID number 1-9 represents measurement of conifer tree heights, ID 10 to 18 and 25 to 40 represents measurement of deciduous tree height and ID 19 to 24 represents the measurement of ground height. From the figure, the general trend shows that the beginner generally underestimate the height measurement. However, the experienced person has slightly overestimated the height measurement at places. It is not clear whether it is an empirical thing or due to individual differences, and whether the differences could be corrected by systematic practice. Figure 3. Experiment area "tipos yx poricnecd —<Baginner Difteronce 1383779111215171921232027 283155 353138 ID number of points Figure 4. Comparison of accuracy evaluation of height measurement Table 1 shows the accuracy evaluation of the test cases. The overall error of the height measurement including both type of trees and ground height was about 1 m for experienced and about 3 m in case of beginner. Hence an average error obtained by considering observations from the both experienced and the beginner observer was about 2 m. Experienced Beginner SD (m) RMS (m) SD (m) RMS (m) : 1.5 1.7 Conifers 0.6 2.9) 0.6 (2.5) x 1.3 37 Deciduous 1.3 (24) 2.4 (-12.0) 0.6 3.9 Ground 0.6 (-0.9) 1.8 (54) Total 12 1.3 2:1 3.4 Table 1. Accuracy results of height measurement From the table it is seen that the person with the prior experience has measured with lower error level. The result shows that for the beginner, measuring tree height for conifer trees was much easier than for the deciduous trees. The top of a conifer tree is easy to be distinguished for the beginner compared to the convex shape of the deciduous trees. Hence beginner had less trouble deciding the tree top. But the tree shape was little of a concern for the person with prior experience. The interesting observation from the experimental study shows that the person with prior experience could measure the ground height with the highest accuracy followed by deciduous tree and conifer trees. However, considering the beginner, it was just opposite. It seems that the beginner will have an ease in measuring the structure with distinct shape than plane like ground or convex shape like deciduous trees. The maximum difference in height measurement observed by the person with a prior experience was 2.9m for a conifer tree, - 2.4m for a deciduous tree and -0.9m at a ground surface. In case of the beginner, the maximum difference in the height measurement for a conifer tree was -2.5m, a deciduous tree was -12.0m and for a ground surface was -5.4m. The maximum difference of -12.0m height was observed at point ID 12. The location of ID 12 is depicted in Figure 3. This was an exceptional error produced due to the carelessness during observation made by the beginner. In general, the experiment shows that the maximum error in tree height measurement by an

Access restriction

Copyright

fullscreen: Technical Commission VIII (B8)

Multivolume work

Volume

Chapter

Chapter

Table of contents

Cite and reuse

Volume

Chapter

Image

Image fragment

Citation links

Citation recommendation