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The computation of foliage clumping index using hemispherical photography
Agricultural and Forest Meteorology, 2009Hemispherical photography (HP) is extensively used for both canopy architecture such as leaf area index (LAI), and solar radiation regime determinations under forest canopies. This is done mainly by assuming that foliage elements occur in a spatially random manner.
Alemu Gonsamo, Petri Pellikka
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Method of segmentation affects leaf inclination angle estimation in hemispherical photography
Agricultural and Forest Meteorology, 2006This paper deals with the issue of segmentation methods in hemispherical photography determining diffuse site factor (DIFFSF) and leaf inclination angle distribution in forest stands simultaneously. Field inclination angle distributions were sampled in pure stands of European beech, hornbeam, sessile oak and silver birch on sites where towers ...
Sven Wagner
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Managing Forest Ecosystems, 2017
The purpose of this chapter is to summarize the key messages from each chapter of the book and the rationale for using hemispherical photography (HP) in the discipline of forest ecology. The chapters describing the theory and methods presented the state of the science and the opportunities for developing applications to forestry and natural resources ...
Richard A Fournier, Fournier Richard A
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The purpose of this chapter is to summarize the key messages from each chapter of the book and the rationale for using hemispherical photography (HP) in the discipline of forest ecology. The chapters describing the theory and methods presented the state of the science and the opportunities for developing applications to forestry and natural resources ...
Richard A Fournier, Fournier Richard A
exaly +2 more sources
Estimation of Leaf Area Index Based on Hemispherical Canopy Photography
2021 IEEE International Geoscience and Remote Sensing Symposium IGARSS, 2021Leaf area index (LAI) is very important for crop growth monitoring, biomass estimation, and many plant growth simulation models. Direct methods are the most accurate, but they have the disadvantage of being extremely time-consuming and labor-intensive as a consequence making them not be the preferred solutions.
Peicheng Wang +6 more
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DETERMINATION OF THE PLANT AREA INDEX OF OLIVE TREES BY HEMISPHERICAL PHOTOGRAPHY
Acta Horticulturae, 1999Destructive measurements of leaf area index (LAT) were compared with values of plant area index (PAI) obtained by hemispherical photography in an unevenly-aged olive orchard in Southern Tuscany, Italy. The measured LAI destructively increased from 0.8 in one-year old plants to 2.8 in 10-year-old trees.
GUCCI, RICCARDO +3 more
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Smartphone based hemispherical photography for canopy structure measurement
2017 International Conference on Optical Instruments and Technology: Optoelectronic Measurement Technology and Systems, 2018The canopy is the most direct and active interface layer of the interaction between plant and environment, and has important influence on energy exchange, biodiversity, ecosystem matter and climate change. The measurement about canopy structure of plant is an important foundation to analyze the pattern, process and operation mechanism of forest ...
Jingwen Zhang +5 more
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Measurement of Forest Structure with Hemispherical Photography
2017This chapter presents the theoretical concepts necessary to link optical sensor data to forest structural attributes . Forest stand architecture is relatively complex and spatially variable, and many approaches can be used for its measurement: from traditional forest measurements in ground plots , to the statistical representation of forest attributes ...
Sylvain G. Leblanc, Richard A. Fournier
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Solar Radiation in Forests: Theory for Hemispherical Photography
2017Solar radiation is not only the main source of energy for life on Earth, but it is also the natural source of light for the optical acquisition of information, such as for vision and photography . Natural sunlight provides the illumination required for taking hemispherical photographs in forests.
Patrick Schleppi, Alain Paquette
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Automatic thresholding for digital hemispherical photography
Canadian Journal of Forest Research, 2004This paper proposes an automatic thresholding method for the discrimination of sky and canopy elements in color hemispherical photographs taken with a digital camera (Nikon Coolpix 950). The exposures for photography were principally determined on the basis of zenith luminance. DIFphoto, which is diffuse transmittance calculated from the hemispherical
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Leaf area index retrieval study with a modelling framework, hemispherical photography and LiDARs
2014 IEEE Geoscience and Remote Sensing Symposium, 2014The availability of experimental data from forest sites, such as foliage density, is limited and is also subject to measurement errors. To address this problem, we designed a study around the use of a modeling framework of virtual forest stands with known architectural attributes using the freeware POV-Ray [1].
Sylvain G. Leblanc, Richard A. Fournier
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