Results 21 to 30 of about 510 (196)

UAV Capability to Detect and Interpret Solar Radiation as a Potential Replacement Method to Hemispherical Photography

Remote Sensing, 2018
Solar radiation is one of the most significant environmental factors that regulates the rate of photosynthesis, and consequently, growth. Light intensity in the forest can vary both spatially and temporally, so precise assessment of canopy and potential ...
Azadeh Abdollahnejad, Dimitrios Panagiotidis, Peter Surový, Iva Ulbrichová   +3 more
doaj   +1 more source

Quantitative digital imaging of banana growth suppression by plant parasitic nematodes. [PDF]

PLoS ONE, 2012
A digital camera fitted with a hemispherical lens was used to generate canopy leaf area index (LAI) values for a banana (Musa spp.) field trial with the aim of establishing a method for monitoring stresses on tall crop plants.
Hugh Roderick, Elvis Mbiru, Danny Coyne, Leena Tripathi, Howard J Atkinson   +4 more
doaj   +1 more source

Quantifying vegetation indices using terrestrial laser scanning: methodological complexities and ecological insights from a Mediterranean forest [PDF]

Biogeosciences, 2023
Accurate measurement of vegetation density metrics including plant, wood and leaf area indices (PAI, WAI and LAI) is key to monitoring and modelling carbon storage and uptake in forests.
W. R. M. Flynn, H. J. F. Owen, S. W. D. Grieve, S. W. D. Grieve, E. R. Lines   +4 more
doaj   +1 more source

Measurement of Crown Cover and Leaf Area Index Using Digital Cover Photography and Its Application to Remote Sensing

Remote Sensing, 2009
Digital cover photography (DCP) is a high resolution, vertical field-of-view method for ground-based estimation of forest metrics, and has advantages over fisheye sensors owing to its ease of application and high accuracy. We conducted the first thorough
Craig Macfarlane, Burak Pekin
doaj   +1 more source

Dynamic Monitoring of the Standard Penetration of PHC Tubular Piles and Analysis of the Construction Effect Based on Monocular Visual Digital Photography

Applied Sciences, 2022
The penetration of large-diameter tubular piles and their relevant construction effect have significant influences on the bearing capacity of piles and nearby buildings (structures).
Guojian Zhang, Zhiyong Liu, Wei Xiong, Sifeng Zhang, Shengzhen Liu, Zhiwei Wang, Yushuai Wang   +6 more
doaj   +1 more source

LAI estimation by direct and indirect methods in Scots pine stands in Northern Steppe of Ukraine

Journal of Forest Science, 2018
Leaf area index (LAI) of Scots pine (Pinus sylvestris Linnaeus) in the Northern Steppe of Ukraine was estimated. LAI estimated directly (LAI d, destructive sampling) was compared with LAI determined by digital hemispherical photography (indirect method ...
Viktoriia LOVYNSKA, Petro LAKYDA, Svitlana SYTNYK, Mykola KHARYTONOV, Iryna PIESTOVA   +4 more
doaj   +1 more source

Hemispherical photography to estimate biophysical variables of cotton

Revista Brasileira de Engenharia Agrícola e Ambiental
The Leaf Area Index (LAI) is a key parameter to evaluate the vegetation spectral response, estimating plant nutrition and water requirements. However, in large fields is difficult to obtain accurate data to LAI determination.
Ziany N. Brandão, João H. Zonta
doaj   +1 more source

Biophysical Variable Retrieval of Silage Maize with Gaussian Process Regression and Hyperparameter Optimization Algorithms

Remote Sensing, 2023
Quantification of vegetation biophysical variables such as leaf area index (LAI), fractional vegetation cover (fCover), and biomass are among the key factors across hydrological, agricultural, and irrigation management studies. The present study proposes
Elahe Akbari, Ali Darvishi Boloorani, Jochem Verrelst, Stefano Pignatti, Najmeh Neysani Samany, Saeid Soufizadeh, Saeid Hamzeh   +6 more
doaj   +1 more source

Evaluation of Digital Hemispherical Photography and Plant Canopy Analyzer for Measuring Vegetation Area Index of Orange Orchards

Journal of Agronomy, 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., Er-Raki, S., Ezzahar, J., /Chehbouni, Abdelghani, Larouni, A., Hanich, L.   +7 more
openaire   +2 more sources

Estimating Savanna Clumping Index Using Hemispherical Photographs Integrated with High Resolution Remote Sensing Images

Remote Sensing, 2017
In contrast to herbaceous canopies and forests, savannas are grassland ecosystems with sparsely distributed individual trees, so the canopy is spatially heterogeneous and open, whereas the woody cover in savannas, e.g., tree cover, adversely affects ...
Jucai Li, Wenjie Fan, Yuan Liu, Gaolong Zhu, Jingjing Peng, Xiru Xu   +5 more
doaj   +1 more source