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Measuring Gap Fraction, Element Clumping Index and LAI in Sierra Forest Stands Using a Full-Waveform Ground-Based LidarThe Echidna Validation Instrument (EVI), a ground-based, near-infrared (1064 nm) scanning lidar, provides gap fraction measurements, element clumping index measurements, effective leaf area index (LAIe) and leaf area index (LAI) measurements that are statistically similar to those from hemispherical photos. In this research, a new method integrating the range dimension is presented for retrieving element clumping index using a unique series of images of gap probability (Pgap) with range from EVI. From these images, we identified connected gap components and found the approximate physical, rather than angular, size of connected gap component. We conducted trials at 30 plots within six conifer stands of varying height and stocking densities in the Sierra National Forest, CA, in August 2008. The element clumping index measurements retrieved from EVI Pgap image series for the hinge angle region are highly consistent (R2=0.866) with those of hemispherical photos. Furthermore, the information contained in connected gap component size profiles does account for the difference between our method and gap-size distribution theory based method, suggesting a new perspective to measure element clumping index with EVI Pgap image series and also a potential advantage of three dimensional Lidar data for element clumping index retrieval. Therefore further exploration is required for better characterization of clumped condition from EVI Pgap image series.
Document ID
20120015673
Acquisition Source
Goddard Space Flight Center
Document Type
Reprint (Version printed in journal)
Authors
Zhao, Feng
(Boston Univ. Boston, MA, United States)
Strahler, Alan H.
(Boston Univ. Boston, MA, United States)
Crystal L. Schaaf
(Boston Univ. Boston, MA, United States)
Yao, Tian
(Boston Univ. Boston, MA, United States)
Yang, Xiaoyuan
(Boston Univ. Boston, MA, United States)
Wang, Zhuosen
(Boston Univ. Boston, MA, United States)
Schull, Mitchell A.
(United States Department of Agriculture Forest Service United States)
Roman, Miguel O.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Woodcock, Curtis E.
(Boston Univ. Boston, MA, United States)
Olofsson, Pontus
(Boston Univ. Boston, MA, United States)
Ni-Meister, Wenge
(Hunter Coll. New York, NY, United States)
Jupp, David L. B.
(Commonwealth Scientific and Industrial Research Organization Canberra, Australia)
Lovell, Jenny L.
(Commonwealth Scientific and Industrial Research Organization Hobart, Australia)
Culvenor, Darius S.
(Commonwealth Scientific and Industrial Research Organization Victoria, Australia)
Newnham, Glenn J.
(Commonwealth Scientific and Industrial Research Organization Victoria, Australia)
Date Acquired
August 26, 2013
Publication Date
August 4, 2012
Publication Information
Publication: Remote Sensing Environment
Publisher: Elsevier Science Publishers
Volume: 125
Subject Category
Earth Resources And Remote Sensing
Report/Patent Number
GSFC.JA.7177.2012
Funding Number(s)
CONTRACT_GRANT: NNX08AE94A
CONTRACT_GRANT: NNG06GI92G
CONTRACT_GRANT: NSF-0923389
Distribution Limits
Public
Copyright
Other

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