Results 21 to 30 of about 751 (246)

Near-infrared digital hemispherical photography enables correction of plant area index for woody material during leaf-on conditions [PDF]

Ecological Informatics
Ecological informatics 79, 102441 (2024).
Luke A. Brown, Harry Morris, Rosalinda Morrone, Morven Sinclair, Owen Williams, Merryn Hunt, Subhajit Bandopadhyay, Xuerui Guo, Haydar Akcay, Jadunandan Dash   +9 more
openaire   +6 more sources

Uncrewed aircraft system spherical photography for the vertical characterization of canopy structural traits. [PDF]

New Phytol, 2022
The plant area index (PAI) is a structural trait that succinctly parametrizes the foliage distribution of a canopy and is usually estimated using indirect optical techniques such as digital hemispherical photography.
Ribas Costa VA, Durand M, Robson TM, Porcar-Castell A, Korpela I, Atherton J.   +5 more
europepmc   +2 more sources

Potential of Automated Digital Hemispherical Photography and Wireless Quantum Sensors for Routine Canopy Monitoring and Satellite Product Validation [PDF]

2021 IEEE International Geoscience and Remote Sensing Symposium IGARSS, 2021
To better characterize the temporal dynamics of vegetation biophysical variables, a variety of automated in situ measurement techniques have been developed in recent years. In this study, we investigated automated digital hemispherical photography (DHP) and wireless quantum sensors, which were installed at two sites under the Copernicus Ground Based ...
Luke A. Brown, Harry Morris, Erika Albero, Ernesto López-Baeza, Frank Tiedemann, Lukas Siebicke, Alexander Knohl, Carolina da Silva Gomes, Gabriele Bai, Christophe Lerebourg, Nadine Gobron, Christian Lanconelli, Marco Clerici, Darius Culvenor, Jadunandan Dash   +14 more
openaire   +2 more sources

Evaluation of digital hemispherical photography and plant canopy analyser for measuring Vegetation area index of orange orchards

, 2009
This study presents the results of an evaluation of two indirect methods (Plant Canopy Analyser (PCA) and hemispherical photographs) for measuring vegetation area index VAI of two orange orchards, differing by their ground fraction cover (fc). The evaluation is based on reference data obtained by destructive measurements on limited samples, which allow
Khabba, S., Duchemin, Benoît, Hadria, R., Ezzahar, J., Chehbouni, Ghani, Lahrouni, A., Hanich, L.   +6 more
core   +4 more sources

Estimating Effective Leaf Area Index of Winter Wheat Based on UAV Point Cloud Data

Drones, 2023
Leaf area index (LAI) is a widely used plant biophysical parameter required for modelling plant photosynthesis and crop yield estimation. UAV remote sensing plays an increasingly important role in providing the data source needed for LAI extraction. This
Jie Yang, Minfeng Xing, Qiyun Tan, Jiali Shang, Yang Song, Xiliang Ni, Jinfei Wang, Min Xu   +7 more
doaj   +1 more source

Continuous estimation of leaf area index and the woody-to-total area ratio of two deciduous shrub canopies using fisheye webcams in a semiarid loessial region of China

Ecological Indicators, 2021
Automatic and accurate measurements of the leaf area index (LAI) can provide information about key parameters of vegetation structure in an ecosystem. Little attention, however, has been paid to LAI dynamics for shrub canopies in both arid and semiarid ...
Xiaotao Niu, Jun Fan, Ruihua Luo, Wei Fu, Hongyou Yuan, Mengge Du   +5 more
doaj   +1 more source

Deriving Leaf Area Index Reference Maps Using Temporally Continuous In Situ Data: A Comparison of Upscaling Approaches

IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 2021
To further progress the validation of global leaf area index (LAI) products, temporally continuous reference data are a key requirement, as periodic field campaigns fail to adequately characterize temporal dynamics.
Luke A. Brown, Booker O. Ogutu, Fernando Camacho, Beatriz Fuster, Jadunandan Dash   +4 more
doaj   +1 more source

The estimation of canopy attributes from digital cover photography by two different image analysis methods

iForest - Biogeosciences and Forestry, 2014
Proximal sensing methods using digital photography have gained wide acceptance for describing and quantifying canopy properties. Digital hemispherical photography (DHP) is the most widely used photographic technique for canopy description.
Chianucci F, Chiavetta U, Cutini A
doaj   +1 more source

TRACKING FOREST AND OPEN AREA EFFECTS ON SNOW ACCUMULATION BY UNMANNED AERIAL VEHICLE PHOTOGRAMMETRY [PDF]

The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2016
Airborne digital photogrammetry is undergoing a renaissance. The availability of low-cost Unmanned Aerial Vehicle (UAV) platforms well adopted for digital photography and progress in software development now gives rise to apply this technique to ...
T. Lendzioch, J. Langhammer, M. Jenicek
doaj   +1 more source

Enhanced gap fraction extraction from hemispherical photography [PDF]

, 2015
Canopy structure can be estimated using gap fraction (GF) data, which can be directly measured with hemispherical photography. However, GF data accuracy is affected by sunlit canopy, multiple scattering, vignetting, blooming, and chromatic aberration ...
Lencinas, José Daniel, Díaz, Gastón Mauro   +1 more
core   +1 more source