Consulta: subjectFacets:"Reflectance"
Registros recuperados: 27
Data/hora: 10/06/2024 16:13:41

Propiedades ópticas de trigo y deficiencias de nitrógeno
Provedor de dados: 32
Autores: Jiménez Meza, Víctor Manuel.
El presente trabajo estudió la relación entre la reflectancia en el espectro visible e infrarrojo cercano y la concentración de nitrógeno en plantas de trigo con el objetivo de encontrar un procedimiento económico, rápido y confiable para conocer el estado de nutrición nitrogenada del cultivo. Las propiedades ópticas de plantas de trigo con diferentes concentraciones de nitrógeno se midieron por cuatro métodos, utilizando un radiómetro, un medidor portátil de clorofila, imágenes obtenidas con cámara digital e imágenes obtenidas con escáner. A partir de las mediciones se generaron modelos de tipo lineal y cuadrático para relacionar las propiedades ópticas con la concentración de nitrógeno en las plantas. El método que utilizó las imágenes de escáner para...
Tipo: Tesis
Palavras-chave: Triticum aestivum L.; Reflectancia; Radiómetro; Diagnóstico de nutrición; Sensores remotos; Maestría; Edafología; Reflectance; Radiometer; Nutritional diagnosis; Remote sensing.
Ano: 2009
URL: http://hdl.handle.net/10521/1657

Reflectancia en hojas de pimiento y fresa para el diagnóstico nutrimental.
Provedor de dados: 32
Autores: Cruz Durán, Jairo Aarón de la.
El desarrollo de los sensores remotos por los países desarrollados, ha permitido generar imágenes satelitales de alta resolución, e instrumentos que proporcionan información precisa: cámaras digitales, espectrómetros, ceptómetros, sensores quánticos lineales, analizadores de dosel, entre otros; así como también equipo de cómputo de alta capacidad y potencia, programas de cómputo para digitalización y análisis de la información en tiempo real. Por lo tanto, el objetivo de esta investigación fue generar nuevas tecnologías que den mayor certidumbre y competitividad a la comercialización, mayor valor de la producción en los mercados futuros, valor de aseguramiento del cultivo y su producción, a través de generación de conocimiento e información en tiempo real...
Palavras-chave: Biotelemática; Espectroradiómetro; Reflectancia; Capsicum annuum; Fragaria x ananassa; Sensores remotos; Escáner de escritorio; Biotelematic; Spectroradiometer; Reflectance; Remote sensing; Desktop scanner; Doctorado; Edafología.
Ano: 2013
URL: http://hdl.handle.net/10521/1902

Identificación de la deficiencia de magnesio en pepino mediante espectroradiometría.
Provedor de dados: 32
Autores: Aguilar Ramírez, María del Rocío.
La utilización de sensores remotos se describe como una técnica de diagnóstico nutrimental promisoria en diferentes aspectos de la agricultura. En este sentido, el presente trabajo tuvo como objetivo determinar estrés por magnesio en pepino, a través de técnicas de percepción remota. Se determinó la reflectancia de hojas recientemente maduras de pepino mediante el uso de Radiómetro, y de imágenes obtenidas con escáner y con cámara digital; también se estimó la concentración de clorofila utilizando un medidor portátil (SPAD 502) y la concentración de magnesio de referencia fue determinada por espectrofotometría de emisión atómica. A partir de estas mediciones se generaron modelos de tipo polinómico, logarítmico y exponencial para relacionar las propiedades...
Palavras-chave: Sensores remotos; Propiedades ópticas; Firmas espectrales; Magnesio; Reflectancia; Remote sensing; Optical properties; Spectral signatures; Magnesium; Reflectance; Maestría; Edafología.
Ano: 2011
URL: http://hdl.handle.net/10521/401

Reflectancia e índices espectrales en pimiento para el diagnóstico nutrimental de nitrógeno
Provedor de dados: 32
Autores: Cruz Durán, Jairo Aarón, de la.
El conocimiento de las firmas espectrales en la valoración de parámetros fisiológicos y nutrimentales, serán de gran utilidad en una agricultura mayormente competitiva. El objetivo de esta investigación consistió en obtener firmas espectrales en hojas de pimiento mediante un espectrómetro e imágenes digitales (escáner) durante el desarrollo del cultivo, para el diagnóstico de estrés por carencias y excesos de nitrógeno. Se determinó la reflectancia de las hojas de pimiento en tres bandas del espectro visible (RGB) y dos del infrarrojo cercano (NR), se obtuvieron imágenes de plantas para la determinación del índice de área foliar (IAF) y se colectaron muestras foliares para el análisis de nitrógeno, el cual se determinó por el método de microkjeldahl. La...
Tipo: Tesis
Palavras-chave: Sensores  remotos; Reflectancia; NDVI; Nitrógeno; Espectrómetro; Escáner; Cámara digital; Firmas espectrales; Nivel crítico de reflectancia; Remote sensors; Reflectance; Nitrogen; NDVI; Nitrogen; Spectrometer; Scanner; Digital camera; Spectral signatures; Critical level of reflectance.
Ano: 2008
URL: http://hdl.handle.net/10521/1659

Reflectancia en hojas de chile manzano (Capsicum pubescens R. y P.) para estimar contenido de nitrógeno.
Provedor de dados: 32
Autores: Gasga Peña, Rosalino.
Con la finalidad de encontrar un procedimiento económico, rápido y confiable que estime el contenido de nitrógeno (N), se estableció un experimento en los invernaderos del Colegio de Postgraduados. La unidad experimental consistió de una planta de chile manzano sembrada en maceta de polietileno negro calibre 600 de 40x45 cm a una distancia de 1.5 m entre hileras y 0.5 m entre macetas. Como sustrato se utilizó tezontle rojo. Se emplearon soluciones nutritivas con cuatro niveles de N: 4, 8, 12 y 16  molc m-3 (en el último tratamiento 2 molc m-3 corresponden a NH4+), a partir de la solución Steiner. El  diseño experimental fue completamente al azar con cuatro repeticiones. En plena fructificación, en cada unidad experimental, se seleccionaron seis hojas y se...
Palavras-chave: Reflectancia; Capsicum pubescens R. y P.; Sensores remotos; Escáner de escritorio; Reflectance; Remote sensing; Desktop scanner; Doctorado; Edafología.
Ano: 2011
URL: http://hdl.handle.net/10521/468

Diagnóstico de deficiencias de nitrógeno y maganesio con imágenes digitales.
Provedor de dados: 32
Autores: Reyes Flores, Maciel.
La detección oportuna de deficiencias nutrimentales en hojas de plantas cultivadas permite tomar medidas correctivas inmediatas asi como predecir rendimientos. Las características espectrales y de textura de las imágenes se pueden utilizar para obtener información y correlacionarlos con el estado nutrimental de elementos esenciales que generan sintomatología similar en hojas de las plantas.  En la presente investigación se estableció un experimento para medir las propiedades espectrales y característica texturales del cultivo de frijol con diferentes concentraciones de nitrógeno y magnesio de imágenes obtenidas con escáner. A partir de los valores de reflectancia se generaron modelos de regresión para asociar la concentración de nitrógeno y magnesio en el...
Palavras-chave: Reflectancia; Discriminación; Espacios de color; Textura; Redes neuronales; Reflectance; Discrimination; Color spaces; Texture; Neural networks; Edafología; Maestría.
Ano: 2013
URL: http://hdl.handle.net/10521/2077

Reflectancia en hojas de chile manzano (Capsicum pubescens R. y P.) para estimar contenido de nitrógeno.
Provedor de dados: 32
Autores: Gasga Peña, Rosalino.
Con la finalidad de encontrar un procedimiento económico, rápido y confiable que estime el contenido de nitrógeno (N), se estableció un experimento en los invernaderos del Colegio de Postgraduados. La unidad experimental consistió de una planta de chile manzano sembrada en maceta de polietileno negro calibre 600 de 40x45 cm a una distancia de 1.5 m entre hileras y 0.5 m entre macetas. Como sustrato se utilizó tezontle rojo. Se emplearon soluciones nutritivas con cuatro niveles de N: 4, 8, 12 y 16  molc m-3 (en el último tratamiento 2 molc m-3 corresponden a NH4+), a partir de la solución Steiner. El  diseño experimental fue completamente al azar con cuatro repeticiones. En plena fructificación, en cada unidad experimental, se seleccionaron seis hojas y se...
Palavras-chave: Reflectancia; Capsicum pubescens R. y P.; Sensores remotos; Escáner de escritorio; Reflectance; Remote sensing; Desktop scanner; Doctorado; Edafología.
Ano: 2011
URL: http://hdl.handle.net/10521/468

Influence of data acquisition geometry on soybean spectral response simulated by the prosail model
Provedor de dados: 70
Autores: Breunig,Fábio M.; Galvão,Lênio S.; Formaggio,Antonio R.; Epiphanio,José C. N.
View angle and directional effects significantly affect reflectance and vegetation indices, especially when daily images collected by large field-of-view (FOV) sensors like the Moderate Resolution Imaging Spectroradiometer (MODIS) are used. In this study, the PROSAIL radiative transfer model was chosen to evaluate the impact of the geometry of data acquisition on soybean reflectance and two vegetation indices (Normalized Difference Vegetation Index - NDVI and Enhanced Vegetation Index -EVI) by varying biochemical and biophysical parameters of the crop. Input values for PROSAIL simulation were based on the literature and were adjusted by the comparison between simulated and real satellite soybean spectra acquired by the MODIS/Terra and hyperspectral...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Leaf area index; NDVI; EVI; Reflectance; MODIS; Remote sensing.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162013000100018

HYPERSPECTRAL SPECTROSCOPY TO DETECT DIFFERENT RESPONSES OF TWO SOYBEAN (GLYCINE MAX) CULTIVARS TO CHARCOAL ROT (MACROPHOMINA PHASEOLINA) TOXIN
Provedor de dados: 70
Autores: Al-Ahmadi,Ameer; Subedi,Arjun; Choudhary,Ruplal; Fakhoury,Ahmad; Watson,Dennis.
ABSTRACT Previous studies have confirmed the potential of hyperspectral spectroscopy (HS) to detect charcoal rot toxin effect on soybean (Glycine max). However, there is no evidence that it can differentiate among difference responses to that effect. This research tested the potential of HS (900–2400 nm) to differentiate different responses to charcoal rot effect caused by the fungal pathogen Macrophomina phaseolina. Known susceptible ‘Pharaoh’ and resistant ‘Spencer’ cultivars of soybean seedlings at the V1 stage were tested, and HS reflectance was measured in each treatment at 0 h (just before toxin treatment), 24 h, and 36 h after toxin treatment. For both cultivars, reflectance generally decreased up to 10% over time for controls and increased for...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Hyperspectral spectroscopy; Glycine Max; Charcoal rot; Ratio; Reflectance.
Ano: 2021
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162021000100078

Reflectancia espectral de solos.
Provedor de dados: 14
Autores: MADEIRA NETTO, J. da S.; BAPTISTA, G. M. de M.
Usando as cores para caracterizar as propriedades dos solos ou atraves de fotografias aereas para a discriminacao de pedoformas , os pedologos, ja ha algum tempo, compreenderam a importancia do uso dos recursos oferecidos pela luz refletida como instrumento para compreender a distribuicao dos solos na paisagem ou para a descricao de suas propriedades. A rapida evolucao da espectroscopia de reflectancia, amplamente explorada no sensoriamento remoto multiespectral, permitiu estender esse uso a comprimentos de onda outros que o visivel. Mais recentemente, com o desenvolvimento da espectroscopia de imageamento o interesse pelas propriedades de reflectancia espectral dos solos ganha nova importancia, por causa da possibilidade de identificar e de mapear...
Tipo: Documentos (INFOTECA-E)
Palavras-chave: Reflectancia; Espectometria; Spectometry.; Cerrado; Solo.; Reflectance; Soil.
Ano: 2000
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/564014

Aplicacion de sensores remotos en la deteccion y evaluacion de plagas y enfermedades en la vegetacion.
Provedor de dados: 14
Autores: SA, I. B.; ANTONIO GARCIA, R. de; ALMOROX, J. A.
Mediante la utilizacion de sensores remotos, la deteccion, registro y analisis de las alteraciones ocurridas en el comportamiente espectral de la cobertura vegetal, permitem caracterizar y evaluar el estado nutricional y fitosanitario de las plantas, detectando incidencias de plagas y enfermedades e inferir posibles carencias nutricionales. En el trabajo se comprueba que el estudio de la reflectancia en la region del infrarrojo cercano permite detectar eficazmente el inicio de danos al producirse cambios en el comportamiento espectral de las plantas. Esta aplicacion permite uma deteccion mas temprana de los danos, pues el ataque de enfermedades o plagas puede ser detectado incluso antes de que la planta presente sintomas visuales de deterioro.
Tipo: Capítulo em livro técnico (INFOTECA-E)
Palavras-chave: Refletancia; Plant; Diseases; Pest; Near infrared; Analysis; Análise; Doença; Planta; Praga; Raio Infravermelho; Sensoriamento Remoto; Vegetação; Reflectance; Remote sensing; Vegetation.
Ano: 1999
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/133846

Rain-derived particles and CDOM distribution along the East Coast of New Caledonia
Provedor de dados: 5
Autores: Dupouy, Cecile; Wattelez, Guillaume; Lefevre, Jerome; Juillot, Farid; Andreoli, Remi; Lille, Didier; Murakami, Hiroshi; Roettgers, Rudiger; Frouin, Robert.
Shortly after strong rains or tropical storms, chlorophyll-a concentration (Chla), turbidity, and colored dissolved organic matter (CDOM) in the lagoon of New Caledonia may be tripled. This effect is visible as far as 50 km offshore. The Eastern Coast of New Caledonia is more impacted than the Western Coast because of its geomorphological structure. Higher frequency and intensity of the rains, and the dominance of highly erosive lateritic formations resulted from deep weathering of ultramafic rocks. At the deeper parts of the lagoon (&gt; 20 m), increases of Chla, turbidity, and CDOM absorption can be detected by satellite imagery with their plumes extending off shore as a result of wind-driven circulation in the lagoon. Such -increases agree with the...
Tipo: Text
Palavras-chave: Minerals; Phytoplankton; CDOM; FDOM; Ocean color; Reflectance; New Caledonia; Tropical Pacific Ocean; Lagoons.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00481/59308/62064.pdf

Surface suspended matter off the Rhone river mouth from visible satellite imagery
Provedor de dados: 5
Autores: Forget, P; Ouillon, S.
The quantification of surface Total Suspended Matter (TSM) off the Rhone river mouth is investigated using SPOT-XS and Landsat-TM images collected in November 1994. The method of satellite data calibration from in situ measurements is discussed. It is based on TSM concentration measurements through filtration of surface water samples and on radiometric data collected with a 256-channel spectroradiometer in the range 400-1100 nm. Empirical relationships between reflectance and TSM concentration are established by linear regression analysis of the data. These relationships are then applied to the image data corrected from atmospheric and surface effects. A good agreement, within a factor of less than two, was found on derived TSM concentration values as...
Tipo: Text
Palavras-chave: Réflectance; Matière en suspension; Télédétection; Panache fluvial; Rhône; Reflectance; Suspended matter; Remote sensing; River plume; Rhone river.
Ano: 1998
URL: http://archimer.ifremer.fr/doc/00325/43637/43228.pdf

Impact assesment of Cyclone Sally on the almost atoll of Aitutaki (cook Islands) by remote sensing
Provedor de dados: 5
Autores: Loubersac, Lionel; Dahl, Arthur; Collote, Pascal; Lemaire, Olivier; D'Ozouville, Laurent.
Damage from tropical cyclones can have major consequences for coral reef structure and ecology, as well as for human communities and human uses of coral reef resources. Remote sensing with high resolution multispectral satellite images can be used to asses large scale cyclone damages on coral reef areas. SPOT images of the almost atoll of AITUTAKI (Cook Islands) taken in june 1986 and february 1987 after the passage of Cyclone Sally near the island in january, were transformed and subjected to a textural analysis, and then compared to asses damage on the reefs and lagoon.New shallow sand and rubble deposits showed increased reflectance, while lower reflectance seemed associated with damage to reef structure, scouring in the lagoon, deposits of terrestrial...
Tipo: Text
Palavras-chave: ICRS 6; Remote sensing; Reflectance; Stresses; Cyclones; Extreme events; Coral reef; Lagoon; Natural System; External Threats &amp; Opportunities.
Ano: 1988
URL: http://archimer.ifremer.fr/doc/00143/25380/23518.pdf

Detailed validation of the bidirectional effect in various Case 1 waters for application to ocean color imagery
Provedor de dados: 5
Autores: Voss, K. J.; Morel, A.; Antoine, D.
The radiance viewed from the ocean depends on the illumination and viewing geometry along with the water properties, and this variation is called the bidirectional effect. This bidirectional effect depends on the inherent optical properties of the water, including the volume scattering function, and is important when comparing data from different satellite sensors. The current model of f/Q, which contains the bidirectional effect, by Morel et al. (2002) depends on modeled, not measured, water parameters, thus must be carefully validated. In this paper we combined upwelling radiance distribution data from several cruises, in varied water types and with a wide range of solar zenith angles. We compared modeled and measured L(view)/L(nadir) and found that the...
Tipo: Text
Palavras-chave: Radiance distribution; Optical properties; Camera system; Reflectance; Instruments.
Ano: 2007
URL: https://archimer.ifremer.fr/doc/00209/32011/30548.pdf

Metodologias de procesamiento de imagenes NOAA-AVHRR y su utilizacion en aplicaciones oceanograficas y biologico-pesqueras en el Atlantico sudoccidental.
Provedor de dados: 20
Autores: Bava, J.
The objective was to use the synoptic capability of NOAA-AVHRR images, and the physical variables inferred from them, in order to achieve spatial and temporal analysis that may allow correlating the satellite variables with oceanographic processes and biological or fishing data. Methodologies of image processing were developed to make possible the use of AVHRR information for the standardized and reliable generation of Sea Surface Temperature (SST) images (using bands 3 to 5 in the thermal infrared), and water reflectance images (using optic bands 1 and 2) as an index of surface turbidity in coastal zones. A methodology was also generated in order to obtain gradients images derived from SST images, which allows the identification of oceanographic fronts....
Tipo: Theses and Dissertations
Palavras-chave: Image processing; Satellite sensing; Surface temperature; Turbidity; Reflectance; Fishery resources; Oceanic fronts; Image processing; Turbidity; Fishery resources; Reflectance.
Ano: 2004
URL: http://hdl.handle.net/1834/1467

Metodologias de procesamiento de imagenes NOAA-AVHRR y su utilizacion en aplicaciones oceanograficas y biologico-pesqueras en el Atlantico sudoccidental.
Provedor de dados: 20
Autores: Bava, J.
The objective was to use the synoptic capability of NOAA-AVHRR images, and the physical variables inferred from them, in order to achieve spatial and temporal analysis that may allow correlating the satellite variables with oceanographic processes and biological or fishing data. Methodologies of image processing were developed to make possible the use of AVHRR information for the standardized and reliable generation of Sea Surface Temperature (SST) images (using bands 3 to 5 in the thermal infrared), and water reflectance images (using optic bands 1 and 2) as an index of surface turbidity in coastal zones. A methodology was also generated in order to obtain gradients images derived from SST images, which allows the identification of oceanographic fronts....
Tipo: Theses and Dissertations
Palavras-chave: Image processing; Satellite sensing; Surface temperature; Turbidity; Reflectance; Fishery resources; Oceanic fronts; Image processing; Turbidity; Fishery resources; Reflectance; Http://aims.fao.org/aos/agrovoc/c_37359; Http://aims.fao.org/aos/agrovoc/c_15043; Http://aims.fao.org/aos/agrovoc/c_2942; Http://aims.fao.org/aos/agrovoc/c_28538.
Ano: 2004
URL: http://hdl.handle.net/1834/1467

Characterization and discrimination of soils by their reflected electromagnetic energy
Provedor de dados: 86
Autores: Demattê,José Alexandre M.
The objective of this work was to verify if reflected energy of soils can characterize and discriminate them. A spectroradiometer (Spectral reflectance between: 400-2,500 nm) was utilized in laboratory. The soils evaluated are located in Bauru region, SP, Brazil, and are classified as Typic Argiudoll (TR), Typic Eutrorthox (LR), Typic Argiudoll (PE), Typic Haplortox (LE), Typic Paleudalf (PV) and Typic Quartzipsamment (AQ). They were characterized by their spectral reflectance as for descriptive conventional methods (Brazilian and International) according to the types of spectral curves. A method for the spectral descriptive evaluation of soils was established. It was possible to characterize and discriminate the soils by their spectral reflectance, with...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Remote sensing; Infrared spectrophotometry; Reflectance; Absorbance.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2002001000013

Leaf optical properties of two liana species Canavalia parviflora Benth. and Gouania virgata Reissk in different light conditions
Provedor de dados: 88
Autores: Sanches,Maria Cristina; Válio,Ivany Ferraz Marques.
Lianas are plants that depend on support to reach some appreciable height, and they represent an important structural component of tropical forests. Although they predominate in clearings and gaps, some species survive in the understory. Changes in irradiance between these environments can affect leaf morphology and absorption of photosynthetic active radiation (PAR). We had examined the effects of different light regimes on leaf optical properties, chlorophyll content, specific leaf area, and leaf surface morphology in young seedlings of Canavalia parviflora Benth. (Fabaceae) and Gouania virgata Reissk (Rhamnaceae). The seedlings were distributed on workbenches covered by different layers of neutral shade netting, thus creating three levels of light...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Leaf absorptance; Lianas; Light conditions; Reflectance; Specific leaf area.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84042006000200013

Digital Soil Mapping of Soil Properties in the “Mar de Morros” Environment Using Spectral Data
Provedor de dados: 90
Autores: Campbell,Patrícia Morais da Matta; Fernandes Filho,Elpídio Inácio; Francelino,Márcio Rocha; Demattê,José Alexandre Melo; Pereira,Marcos Gervasio; and,Clécia Cristina Barbosa Guimarães; Pinto,Luiz Alberto da Silva Rodrigues.
ABSTRACT Quantification of soil properties is essential for better understanding of the environment and better soil management. The conventional techniques of laboratory analysis are sometimes costly and detrimental to the environment. Thus, development of new techniques for soil analysis that do not generate residues, such as spectroscopy, is increasingly necessary as a viable way to estimate a wide range of soil properties. The objective of this study was to predict the levels of organic carbon (OC), clay, and extractable phosphorus (P), from the spectral responses of soil samples in the visible and near infrared (Vis-NIR), medium infrared (MIR), and Vis-NIR-MIR using different preprocessing methods combined with five prediction models. Soil samples were...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Spectral analysis; Reflectance; Chemometrics.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832018000100314

Using a field radiometer to estimate instantaneous sky clearness
Provedor de dados: 91
Autores: Souza,Eduardo G.; Scharf,Peter; Sudduth,Ken A.; Hipple,James. D.
Reflectance measurements of crop plants and canopies show promise for guiding within-season, variable-rate nitrogen (N) application. Most research results have been obtained around solar noon with clear skies. However, for practical application, the system must work under cloudy skies or away from solar noon. The objective of this work was to assess the effect of cloud conditions on reflectance measurements of a corn canopy. The approach was to estimate an instantaneous sky clearness index (ICI) which could be used to correct field radiometer data for variations in cloud cover, such that the same reflectance reading would be obtained (and the same N recommendation made) for the same plants regardless of cloud conditions. Readings were taken from morning...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Precision agriculture; Nitrogen management; Reflectance; Cloud.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662006000200018

Diet authentication in sheep from the composition of animal tissues and products
Provedor de dados: 96
Autores: Prache,Sophie.
There is currently an increased consumer demand for information on herbivore production factors, particularly animal diet. To meet these demands, producers and commercial entities develop specifications via quality certifications. There is therefore a need for analytical tools that may guarantee that the specification commitments have been fully met or to help with constructing them. The present paper reviews the current state of knowledge concerning diet authentication in sheep meat and milk, the different approaches that have been investigated, some leading examples concerning the discrimination of contrasting feeding situations, together with the persistence of some diet markers in the event of changes in animals' diet. The nature of the diet strongly...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Authentication; Diet tracers; Meat; NIR spectroscopy; Pasture-feeding; Reflectance.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982009001300036

In situ separation of soil types along transects employing Vis-NIR sensors: a new view of soil evaluation
Provedor de dados: 124
Autores: Fiorio,Peterson Ricardo; Demattê,José Alexandre Melo; Nanni,Marcos Rafael; Genú,Aline Marques; Martins,Juliano Araujo.
Soil components, such as organic matter, the levels and form of iron oxides, moisture and texture, influence the interaction of the soil with electromagnetic energy, so that knowledge of the energy reflected by different classes of soil is therefore of help in their discrimination. The aim of this study was to evaluate the possibility of differentiating classes of soils along two transects, by means of the field spectral behaviour of different classes, using both visual and multivariate statistical analysis. Equidistant points were marked along the transects, 100 m apart, where geo-referenced soil samples were collected from the surface layer at a depth of 0 to 0.20 m. In the area under study, ten classes of soil were described by means of laboratory...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Remote sensing; Soil survey; Reflectance; Soil spectroradiometry.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902014000300002

Hyperspectral remote sensing as an alternative to estimate soil attributes
Provedor de dados: 124
Autores: Demattê,José A. M.; Alves,Marcelo Rodrigo; Gallo,Bruna Cristina; Fongaro,Caio T.; Souza,Arnaldo Barros e; Romero,Danilo Jefferson; Sato,Marcus Vinicius.
Minimizing environmental impacts and increasing crop productivity depend mainly on the knowledge of chemical, physical and mineralogical characteristics of the soil attributes. However, traditional methods are timeconsuming and costly. The objective of this study was to determine and validate a method to quantify soil attributes using UV-Vis-NIR Spectroscopy as an alternative to conventional methods of soil analyses. The work comprised two main phases: (1) creation and calibration of statistical models to determine the soil attributes derived from spectral data extracted from soil samples collected in area 1, (2) validation of statistical models in area 2 and correlations between the estimated and observed values (conventional method) for each soil...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Reflectance; Soil analysis; Remote Sensing.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902015000200223

Prediction of soil chemical attributes using optical remote sensing - doi: 10.4025/actasciagron.v33i4.7975
Provedor de dados: 1
Autores: Genú, Aline Marques; Universidade Estadual do Centro-Oeste; Demattê, José Alexandre Melo; Universidade de São Paulo.
Soil fertility variability management is one of the pioneering and important areas in which Precision Agriculture has been commercially applied. Consequently, the objective of this work was to predict soil chemical attributes through spectral responses. The 1,000 ha study area used for this report was located in Uberlândia, Minas Gerais State, Brazil. Thirty sampling points were established, at which the soil was collected at 3 different depths. The samples were chemically and physically analyzed and the radiometric data obtained in the 400 – 2500 nm range. Multiple regression equations were generated for sum of bases, cation exchange capacity, base saturation, aluminum saturation, pH, P, K, Ca, Mg, Al, and H, all using 60 soil samples. H, Al, m%, and pH...
Palavras-chave: Agronoma soil chemistry; Reflectance; Laboratory sensor Solos e Nutrição de Plantas soil chemistry; Reflectance; Laboratory sensor.
Ano: 2011
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/7975

Optical properties of grapevine leaves: reflectance, transmittance, absorptance and chlorophyll concetration
Provedor de dados: 115
Autores: Cabello-Pasini,Alejandro; Macías-Carranza,Víctor.
Leaf absorptance (A), transmittance (T) and reflectance (R) of visible solar radiation strongly correlate with chlorophyll concentration in a number of plant species, however, little is known about the optical properties of grapevine leaves. Consequently, the objective of this study was to evaluate the optical properties of intact leaves for estimating chlorophyll concentration in Cabernet Sauvignon, Merlot and Tempranillo vaieties. Leaves from Cabernet Sauvignon, Merlot and Tempranillo vines were collected at San Antonio de las Minas, Baja California, México, in 2009, and A, T and R determined with a spectroradiometer. While leaf age played a significant role on the leaf chlorophyll concentration, the chlorophyll a+b concentration vs. R, T and A...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Absorptance; Chlorophyll; Reflectance; Transmittance; Optical properties.
Ano: 2011
URL: http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S1405-31952011000800007

In-flight absolute calibration of the CBERS-2 CCD sensor data
Provedor de dados: 42
Autores: Ponzoni,Flávio J.; Zullo Junior,Jurandir; Lamparelli,Rubens A.C.
Since the first images of the sensors on board of CBERS-2 (China-Brazil Earth Resources Satellite) satellite were made available by the National Institute for Space Research (INPE), users have asked information about the conversion of image digital numbers to physical data (radiance or reflectance). This paper describes the main steps that were carried out to calculate the in-flight absolute calibration coefficients for CBERS-2 CCD level 2 (radiometric and geometric correction) images considering the reflectance-based method. Remarks about the preliminary evaluation of these coefficients application are also presented.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Absolute calibration; CBERS-2; CCD; Reflectance.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652008000200015