Results 21 to 30 of about 31,615 (293)

Comparison of Seven Inversion Models for Estimating Plant and Woody Area Indices of Leaf-on and Leaf-off Forest Canopy Using Explicit 3D Forest Scenes

Remote Sensing, 2018
Optical methods require model inversion to infer plant area index (PAI) and woody area index (WAI) of leaf-on and leaf-off forest canopy from gap fraction or radiation attenuation measurements.
Jie Zou, Yinguo Zhuang, Francesco Chianucci, Chunna Mai, Weimu Lin, Peng Leng, Shezhou Luo, Bojie Yan   +7 more
doaj   +1 more source

A Modified Beer–Lambert–Bouguer Law for Nonrandom Distributions and Its Application in Gap Probability Calculations for Heterogeneous Canopies

Journal of Advances in Modeling Earth Systems, 2023
The three‐dimensional (3D) structure of vegetation canopy strongly influence the absorption and reflection of radiation at the land surface. The gap probability is one primary indicator of the canopy structure.
Qing He, Daren Lyu
doaj   +1 more source

Seasonal Effect of the Vegetation Clumping Index on Gross Primary Productivity Estimated by a Two-Leaf Light Use Efficiency Model

Remote Sensing, 2023
Recently, light use efficiency (LUE) models driven by remote sensing data have been widely employed to estimate the gross primary productivity (GPP) of different terrestrial ecosystems at global or regional scales.
Zhilong Li, Ziti Jiao, Chenxia Wang, Siyang Yin, Jing Guo, Yidong Tong, Ge Gao, Zheyou Tan, Sizhe Chen   +8 more
doaj   +1 more source

Cosmic reionization constraints on the nature of cosmological perturbations [PDF]

, 2006
We study the reionization history of the Universe in cosmological models with non-Gaussian density fluctuations, taking them to have a renormalized $\chi^2$ probability distribution function parametrized by the number of degrees of freedom, $\nu$.
Avelino, Pedro P, Liddle, Andrew R
core   +2 more sources

Developing a 3D clumping index model to improve optical measurement accuracy of crop leaf area index

Field Crops Research, 2022
The clumping index reflects the state of leaf aggregation, which is an essential structural parameter for calculating the leaf area index (LAI). Most of the previous clumping index models are one-dimensional (1D) models, in which the input parameters are measured in a long truncated manner (i.e., one-dimensional measurement path, line data), so that is
Ma, Xu, Wang, Tiejun, Lu, Lei, Huang, Huaguo, Ding, Jianli, Zhang, Fei   +5 more
openaire   +2 more sources

Real-Time Software for the Efficient Generation of the Clumping Index and Its Application Based on the Google Earth Engine

Remote Sensing, 2022
Canopy clumping index (CI) is a key structural parameter related to vegetation phenology and the absorption of radiation, and it is usually retrieved from remote sensing data based on an empirical relationship with the Normalized Difference between ...
Yu Li, Hongliang Fang
doaj   +1 more source

The Clumping Transition in Niche Competition: a Robust Critical Phenomenon [PDF]

, 2010
We show analytically and numerically that the appearance of lumps and gaps in the distribution of n competing species along a niche axis is a robust phenomenon whenever the finiteness of the niche space is taken into account.
Bak P, E van Nes, Egerton F N, Gilmore R, H Fort, Havlicek T D, M Scheffer, May R M, May R M, Mitchel M, Pielou E C, Segura A Calliari D Kruk C Conde D Bonilla S Fort H, Thom R, Voit G M   +13 more
core   +2 more sources

Influence of Snow on the Magnitude and Seasonal Variation of the Clumping Index Retrieved from MODIS BRDF Products

Remote Sensing, 2018
The foliage Clumping Index (CI) is an important vegetation structure parameter that allows for the accurate separation of sunlit and shaded leaves in a canopy.
Yadong Dong, Ziti Jiao, Siyang Yin, Hu Zhang, Xiaoning Zhang, Lei Cui, Dandan He, Anxin Ding, Yaxuan Chang, Shengtian Yang   +9 more
doaj   +1 more source

Evaluation of MODIS LAI/FPAR product Collection 6. Part 2: Validation and intercomparison [PDF]

, 2016
The aim of this paper is to assess the latest version of the MODIS LAI/FPAR product (MOD15A2H), namely Collection 6 (C6). We comprehensively evaluate this product through three approaches: validation with field measurements, intercomparison with other ...
Chen, Chi, Knyazikhin, Yuri, Liu, Zhao, Myneni, Ranga B., Nemani, Ramakrishna R., Park, Taejin, Yan, Guangjian, Yan, Kai, Yang, Bin   +8 more
core   +2 more sources

Validating canopy clumping retrieval methods using hemispherical photography in a simulated Eucalypt forest [PDF]

, 2017
The so-called clumping factor (Ω) quantifies deviation from a random 3D distribution of material in a vegetation canopy and therefore characterises the spatial distribution of gaps within a canopy.
Armston, Armston, Bréda, Chen, Chen, Chen, Chen, Chen, Chen, Chen, Chianucci, de Wit, Disney, Fernandes, Fournier, Franklin, Frazer, GCOS, Gonsamo, Gonsamo, Gonsamo, Jacobs, John D. Armston, Jonckheere, Jonckheere, Jupp, Kalácska, Kucharik, Lang, Law, Leblanc, Leblanc, Leblanc, Leblanc, Leblanc, Lewis, Lola Suarez, Macfarlane, Mariela Soto-Berelov, Mathias Disney, Michael J. Hill, Miller, Monsi, Monteith, Morisette, Newnham, Neyman, Nilson, Nilson, Phil Wilkes, Piayda, Pielou, Pisek, Pisek, Pisek, Pisek, Ross, Ryu, Schaefer, Simon D. Jones, Spanner, Walter, Weiss, Widlowski, William Woodgate, Wilson, Woodgate, Woodgate, Woodgate, Woodgate, Zhao, Zheng   +71 more
core   +4 more sources