نتایج جستجو برای: vegetation indices

تعداد نتایج: 127108  

2015
Sharon Leigh Cundill Harald van der Werff Mark van der Meijde

The use of data from multiple sensors is often required to ensure data coverage and continuity, but differences in the spectral characteristics of sensors result in spectral index values being different. This study investigates spectral response function effects on 48 spectral indices for cultivated grasslands using simulated data of 10 very high spatial resolution sensors, convolved from field...

2001
JIMMY O. ADEGOKE ANDREW M. CARLETON

Satellite-derived vegetation indices extracted over locations representative of midwestern U.S. cropland and forest for the period 1990–94 are analyzed to determine the sensitivity of the indices to neutron probe soil moisture measurements of the Illinois Climate Network (ICN). The deseasoned (i.e., departures from multiyear mean annual cycle) soil moisture measurements are shown to be weakly c...

Journal: :J. Imaging 2016
Jonathan Van Beek Laurent Tits Ben Somers Tom Deckers Pieter Janssens Pol Coppin

Stress-related biophysical variables of capital intensive orchard crops can be estimated with proxies via spectral vegetation indices from off-nadir viewing satellite imagery. However, variable viewing compositions affect the relationship between spectral vegetation indices and stress-related variables (i.e., chlorophyll content, water content and Leaf Area Index (LAI)) and could obstruct chang...

2004
Driss Haboudane John R. Miller Elizabeth Pattey Pablo J. Zarco-Tejada Ian B. Strachan

A growing number of studies have focused on evaluating spectral indices in terms of their sensitivity to vegetation biophysical parameters, as well as to external factors affecting canopy reflectance. In this context, leaf and canopy radiative transfer models are valuable for modeling and understanding the behavior of such indices. In the present work, PROSPECT and SAILH models have been used t...

2016
Laleh PARVIZ

The aim of this research was to determine the effective drought indices such as NDVI, VCI, EVI, TVX, VTCI, VHI, TCI and NVSWI based on some criteria. The satellite-based drought indices have different data from vegetation and temperature conditions. Linear and trend analysis showed that satellite-based drought indices based on vegetation condition were not more efficient indices such as NDVI an...

2006
J. Verrelst B. Koetz M. Kneubühler M. Schaepman

View angle effects present in vegetation indices are either being seen as unwanted information or as an additional source of information. However, the magnitude of these angular effects remains for most indices unknown. We use the ESA-mission CHRISPROBA (Compact High Resolution Imaging Spectrometer–Project for On-board Autonomy) providing spaceborne imaging spectrometer and multidirectional dat...

2008
Shauna Nelson Keith T. Weber

Vegetation indices are commonly applied to remote sensing data and their application is based upon well established image processing theory and methodology. Simple band ratio vegetation indices allow for consistent and uniform data processing and analysis. However, it was hypothesized that many of these standard vegetation indices (e.g., SR, NDVI and SAVI) may not produce results any different ...

Forest ecosystems are among the largest terrestrial carbon reservoirs on our planet earth thus playing a vital role in global carbon cycle. Presently, remote sensing techniques provide proper estimates of forest biomass and quantify carbon stocks. The present study has explored Landsat-8 sensor product and evaluated its application in biomass mapping and estimation. The specific objectives were...

Forest’s ecosystem is one of the most important carbon sink of the terrestrial ecosystem. Remote sensing technology provides robust techniques to estimate biomass and solve challenges in forest resource assessment. The present study explored the potential of Sentinel-2 bands to estimate biomass and comparatively analyzed of red-edge band based and broadband derived vegetation indices. Broadband...

2013
Xinfeng Yao Xia Yao Wenqing Jia Yongchao Tian Jun Ni Weixing Cao Yan Zhu

Various sensors have been used to obtain the canopy spectral reflectance for monitoring above-ground plant nitrogen (N) uptake in winter wheat. Comparison and intercalibration of spectral reflectance and vegetation indices derived from different sensors are important for multi-sensor data fusion and utilization. In this study, the spectral reflectance and its derived vegetation indices from thr...

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