نتایج جستجو برای: we adopted the normalized difference vegetation index ndvi

تعداد نتایج: 16179067  

Journal: :Remote Sensing 2012
Zhaoqin Li Xulin Guo

Grasslands hold varied grazing capacity, provide multiple habitats for diverse wildlife, and are a key component of carbon stock. Research has indicated that grasslands are experiencing effects related to recent climate trends. Understanding how grasslands respond to climate variation thus is essential. However, it is difficult to separate the effects of climate variation from grazing. This stu...

2010
I. Herrmann A. Pimstein A. Karnieli Y. Cohen V. Alchanatis J. D. Bonfil Jacob Blaustein

This study aims to explore the potential and advantage of using the red-edge spectral bands of the forthcoming Vegetation and Environmental New micro Spacecraft (VENμS) for assessing Leaf Area Index (LAI) in field crops. Field spectral data were collected from experimental plots of wheat and potato at the northwestern Negev, Israel. These data were resampled to the VENμS bands being used for ca...

2013
GAN Wenxia SHEN Huanfeng ZHANG Liangpei GONG Wei

Medium Resolution NDVI( Normalized Difference Vegetation Index) from different sensor systems such as Landsat, SPOT, ASTER, CBERS and HJ-1A/1B satellites provide detailed spatial information for studies of ecosystems, vegetation biophysics, and land cover. Limitation of sensor designs, cloud contamination, and sensor failure highlighted the need to normalize and integrate NDVI from multiple sen...

Journal: :Remote Sensing 2017
Kai Liu Hongbo Su Xueke Li

Quantifying vegetation fractional cover (VFC) and assessing its role in heat fluxes modeling using medium resolution remotely sensed data has received less attention than it deserves in heterogeneous urban regions. This study examined two approaches (Normalized Difference Vegetation Index (NDVI)-derived and Multiple Endmember Spectral Mixture Analysis (MESMA)-derived methods) that are commonly ...

2006
J. Kim Q. Guo D. D. Baldocchi M. Y. Leclerc L. Xu H. P. Schmid

In this paper, we describe the process of assessing tower footprint climatology, spatial variability of site vegetation density based on satellite image analysis, and sensor location bias in scaling up to 1 km 1 km patch. Three flat sites with different vegetation cover and surface heterogeneity were selected from AmeriFlux tower sites: the oak/grass site and the annual grassland site in a sava...

Journal: :Remote Sensing 2017
Nir Y. Krakauer Tarendra Lakhankar José D. Anadón

Global change affects vegetation cover and processes through multiple pathways. Long 1 time series of surface land surface properties derived from satellite remote sensing give unique 2 abilities to observe these changes, particularly in areas with complex topography and limited research 3 infrastructure. Here, we focus on Nepal, a biodiversity hotspot where vegetation productivity is 4 limited...

Journal: :Remote Sensing 2015
Sergio Vicente-Serrano Daniel Cabello Miquel Tomás-Burguera Natalia Martín-Hernández Santiago Beguería Cesar Azorin-Molina Ahmed El Kenawy

We analyzed potential land degradation processes in semiarid regions worldwide using long time series of remote sensing images and the Normalized Difference Vegetation Index (NDVI) for the period 1981 to 2011. The objectives of the study were to identify semiarid regions showing a marked decrease in potential vegetation activity, indicative of the occurrence of land degradation processes, and t...

2013
Richard Tran Mills Jitendra Kumar Forrest M. Hoffman William W. Hargrove Joseph P. Spruce Steven P. Norman

We investigated the use of principal components analysis (PCA) to visualize dominant patterns and identify anomalies in a multi-year land surface phenology data set (231 m × 231 m normalized difference vegetation index (NDVI) values derived from the Moderate Resolution Imaging Spectroradiometer (MODIS)) used for detecting threats to forest health in the conterminous United States (CONUS). Our g...

2009
Seung-Chul Yoon Richard B. Russell Chi Thai

Three-dimensional (3D) measurements of whole plants may provide detailed structure information about plant health and also complement existing X-ray systems for the below-ground part. In addition to this structure characterization of plants, spectral information may also biochemically characterize plants' health. A stereo vision technique is a cost-effective and rapid imaging technique for meas...

Journal: :JCM 2014
Md. Z. Rahman Leonid Roytman M. Nazrul Islam

—This paper investigated the normalized difference vegetation index (NDVI) stability in the NOAA/NESDIS Global Vegetation Index (GVI) data during 1982-2003, which was collected from five NOAA series satellites. An empirical distribution function (EDF) was developed to eliminate the long-term inaccuracy of the NDVI data derived from the AVHRR sensor on NOAA polar orbiting satellite. The instabi...

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