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Spectral reflection indices as a potential indirect selection criteria for wheat yield under irrigation
- Crop Science
, 2006
"... The objectives of this study were to assess the potential of using spectral reflectance indices (SRI) as an indirect selection tool to dif-ferentiate spring wheat (Triticum aestivum L.) genotypes for grain yield under irrigated conditions. This paper demonstrates only the first step in using the SRI ..."
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The objectives of this study were to assess the potential of using spectral reflectance indices (SRI) as an indirect selection tool to dif-ferentiate spring wheat (Triticum aestivum L.) genotypes for grain yield under irrigated conditions. This paper demonstrates only the first step in using the SRI as indirect selection criteria by reporting genetic variation for SRI among genotypes, the effect of phenology and year on SRI and their interaction with genotypes, and the correlations be-tween SRI and grain yield and yield components of wheat. Three field experiments—15 CIMMYT globally adapted genotypes (GHIST), 25 random F3–derived lines (RLs1), and 36 random F3–derived lines (RLs2)—were conducted under irrigated conditions at the CIMMYT research station in northwest Mexico in three different years. Five pre-viously developed SRI (photochemical reflectance index [PRI], water index [WI], red normalized difference vegetation index [RNDVI],
Evaluation of long-term NDVI time series derived from Landsat data through blending with MODIS data
- Atmósfera 2012
"... El objetivo de este estudio es capitalizar el detalle espacial del Landsat y la regularidad temporal de las adquisiciones de MODIS utilizando una aproximación de fusión (Spatial and Temporal Adaptive Reflec-tance Fusion Model, STARFM). Específicamente, se pronosticó la reflectancia de superficie de ..."
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El objetivo de este estudio es capitalizar el detalle espacial del Landsat y la regularidad temporal de las adquisiciones de MODIS utilizando una aproximación de fusión (Spatial and Temporal Adaptive Reflec-tance Fusion Model, STARFM). Específicamente, se pronosticó la reflectancia de superficie de 30 m del Landsat-7 Enhanced Thematic mapper plus (ETM+) para un período de ocho años (2002-2009) como el producto de la reflectancia observada de superficie (MOD09Q1) ETM+ y MODIS sobre los datos ETM+ observados y pronosticados. El análisis de pixeles de los datos ETM+ observados de las estaciones de cultivo de invierno y verano mostró que el método de predicción fue más preciso para el infrarrojo cercano (NIR, por sus siglas en inglés) (media r2 = 0.87, p ≤ 0.01) en comparación con la banda del rojo ( media r2 = 0.65, p ≤ 0.01). Se calculó el índice de vegetación en diferencias normalizadas (NDVI, por sus siglas en inglés) de la reflectancia Landsat observada y pronosticada. Se comparó la diferencia entre el NDVI de los datos ETM+ observados y pronosticados (predicción residual) y los residuales temporales de los datos Landsat y MODIS en dos fechas diferentes. Se encontró que que los residuales pronosticados para el NDVI (valor de la media espacial 0.0085) fueron significativamente menores que los residuales temporales (valor de la media espacial para MODIS 0.056 y 0.051 para ETM+ observados) lo que implica que el método de predicción fue mejor que la sustitución temporal de pixeles. Al investigar la tendencia de los valores sintéticos ETM+ del
unknown title
, 2011
"... How to cite Complete issue More information about this article Journal's homepage in redalyc.org Scientific Information System ..."
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How to cite Complete issue More information about this article Journal's homepage in redalyc.org Scientific Information System
AN ABSTRACT OF THE THESIS OF
, 1999
"... Abstract approved: Numbers of wild Canada geese (Branta canadensis) have increased dramatically during the past 30 years in the lower Columbia and Willamette Valley systems. The damage they cause by grazing and trampling plants can be substantial. The objectives of this research were to: Develop met ..."
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Abstract approved: Numbers of wild Canada geese (Branta canadensis) have increased dramatically during the past 30 years in the lower Columbia and Willamette Valley systems. The damage they cause by grazing and trampling plants can be substantial. The objectives of this research were to: Develop methods that provide reliable estimates of goose impact on wheat yield and quality, and Develop methods to separate goose damage from other factors that lower yield such as poor soil or waterlogging. To document grazing impacts, color aerial photography was combined with Global Positioning System (GPS) and precision farming technology. Field-scale color aerial photographs (1:14,000 scale) were acquired four times during each
Article A Framework for Defining Spatially Explicit Earth Observation Requirements for a Global Agricultural Monitoring Initiative (GEOGLAM)
"... www.mdpi.com/journal/remotesensing ..."
REMOTE SENS. ENVIRON. 49:212-223 (1994) Photographic and Videographic Observations for Determining and Mapping the Response of
"... Better ways are needed to assess the extent and severity of soil salinity in fields in terms of economic impact on crop production and effectiveness of reclamation efforts. Procedures to help meet these needs were developed from soil salinity, plant height and boll counts, and digitized color infrar ..."
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Better ways are needed to assess the extent and severity of soil salinity in fields in terms of economic impact on crop production and effectiveness of reclamation efforts. Procedures to help meet these needs were developed from soil salinity, plant height and boll counts, and digitized color infrared aerial photography and videography ac-quired during midboll set development stage for four salt-affected cotton (Gossypium hirsutum, L.) fields in the San Joaquin Valley of California. Unsupervised classi-jication procedures were used to produce seven-category spectral maps by field. Regression equations were devel-oped from salinity measurements in the surface 30 cm (EC1) at 100-200 sample sites per field and the photogra-phy and videography digital counts at those same sites. The equations were used to estimate the salinity of each of the approximately 100,000 pixels per field, and the salinity categories corresponding to the spectral ones were mapped. The spectral classification maps and the estimated salinity maps corresponded well. Boll counts, made at about 20 sites perjield, were converted to lint yield and regressed on NDVl from both the photography and videography; the correlation coefficient (r) was 0.72 for video and 0.73 for the photographic data. Lint yields decreased by 43 f 10 kg ha- ’ per dS mm1 increase in ECl, or $52 f 12 ha- ’ at current market prices. Our results illustrate very practical ways to combine image analysis capability, spectral observations, and ground truth to map and quantify the severity of soil salinity and its effects on crops.
ESTIMATES OF ABSORBED RADIATION AND LEIP AREA
"... Estimating the quantity and quality of vegetation is a primary goal of remote sensing. The impact of changing sun-view-target geometry on spectral measures of vegetative amount (vegetative indices, VIs) has been a major source of concern with this pursuit. A field experiment was conducted to test th ..."
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Estimating the quantity and quality of vegetation is a primary goal of remote sensing. The impact of changing sun-view-target geometry on spectral measures of vegetative amount (vegetative indices, VIs) has been a major source of concern with this pursuit. A field experiment was conducted to test the statistical significance of solar and view zenith angle effects on the regression coefficients of relationships established between the simple ratio and normalized difference vegetation indices and the biophysical parameters fraction of absorbed photosynthetically active radiation (APAR) and leaf area index (LAI). Measurements of spectral
