|
|
|
| Registros recuperados: 14 | |
|
|
| PADRÓN,EVA; NAVARRO-CERRILLO,RAFAEL M. |
| The significance of field work in remote sensing studies when applied to large areas has often been underestimated. The combination of specific forest inventories for the estimation of aboveground biomass in large dry tropical forest areas with remote sensor data has scarcely been explored to date. In this work, a systematic, stratified forest inventory involving 100 X 100 m square plots in an area of Peruvian Prosopis pallida dry forest, roughly one million hectares in size in the Piura province (Peru) has been compiled. The inventory encompassed the principal silvicultural variables defining the ecosystem studied, which were used in allometric equations for the different species, genera and plant associations in the area in order to estimate the amount... |
| Tipo: Journal article |
Palavras-chave: Prosopis pallida; Landsat 7 ETM+; Vegetation indices; Biomass estimation. |
| Ano: 2007 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2007000100004 |
| |
|
|
| Zenteno Cruz, Guillermo Alberto. |
| Los productores de caña de azúcar buscan constantemente formas de reducir costos, aumentar la productividad y los rendimientos, pero en general, son pocas las herramientas que se están aplicando para tal fin. Por otra parte, es cada vez más importante la predicción temprana del rendimiento de los cultivos que permita una planificación de políticas agrícolas y de seguridad alimentaria en una economía de mercado globalizado. Con el propósito de calibrar una metodología para enfrentar estos problemas, la presente investigación se llevó a cabo en la zona de abasto del Ingenio Emiliano Zapata, en Morelos, México, en una superficie de 10, 664 hectáreas, durante el ciclo agrícola 2009-2010. El propósito del estudio fue determinar una función matemática para... |
|
Palavras-chave: Predicción temprana; Indices de vegetación; Estrés hídrico; Evapotranspiración; Saccharum officinarum; Early prediction; Vegetation indices; Water stress; Evapotranspiración; Maestría; Hidrociencias. |
| Ano: 2012 |
URL: http://hdl.handle.net/10521/737 |
| |
|
| |
|
| |
|
| |
|
|
| Xavier,Alexandre Cândido; Rudorff,Bernardo Friedrich Theodor; Moreira,Mauricio Alves; Alvarenga,Brummer Seda; Freitas,José Guilherme de; Salomon,Marcus Vinicius. |
| Hyperspectral crop reflectance data are useful for several remote sensing applications in agriculture, but there is still a need for studies to define optimal wavebands to estimate crop biophysical parameters. The objective of this work is to analyze the use of narrow and broad band vegetation indices (VI) derived from hyperspectral field reflectance measurements to estimate wheat (Triticum aestivum L.) grain yield and plant height. A field study was conducted during the winter growing season of 2003 in Campinas, São Paulo State, Brazil. Field canopy reflectance measurements were acquired at six wheat growth stages over 80 plots with four wheat cultivars (IAC-362, IAC-364, IAC-370, and IAC-373), five levels of nitrogen fertilizer (0, 30, 60, 90, and 120 kg... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Remote sensing; Agriculture; Vegetation indices. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162006000200004 |
| |
|
| |
|
|
| Bagheri,Nikrooz; Ahmadi,Hojjat; Alavipanah,Seyed Kazem; Omid,Mahmoud. |
| The objective of this work was to evaluate the use of multispectral remote sensing for site-specific nitrogen fertilizer management. Satellite imagery from the advanced spaceborne thermal emission and reflection radiometer (Aster) was acquired in a 23 ha corn-planted area in Iran. For the collection of field samples, a total of 53 pixels were selected by systematic randomized sampling. The total nitrogen content in corn leaf tissues in these pixels was evaluated. To predict corn canopy nitrogen content, different vegetation indices, such as normalized difference vegetation index (NDVI), soil-adjusted vegetation index (Savi), optimized soil-adjusted vegetation index (Osavi), modified chlorophyll absorption ratio index 2 (MCARI2), and modified triangle... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aster; Nitrogen content; Near infrared; Multispectral response; Precision agriculture; Vegetation indices. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2013001000011 |
| |
|
|
| Moraes,André Geraldo de Lima; Carvalho,Daniel Fonseca de; Antunes,Mauro Antonio Homem; Ceddia,Marcos Bacis. |
| Abstract: The objective of this work was to evaluate the relationship between different remote sensing data, derived from satellite images, and interrill soil losses obtained in the field by using a portable rainfall simulator. The study was carried out in an area of a hydrographic basin, located in Médio Paraíba do Sul, in the state of Rio de Janeiro - one of the regions most affected by water erosion in Brazil. Evaluations were performed for different vegetation indices (NDVI, Savi, EVI, and EVI2) and fraction images (FI), derived from linear spectral mixture analysis (LSMA), obtained from RapidEye, Sentinel2A, and Landsat 8 OLI images. Vegetation indices are more adequate to predict soil loss than FI, highlighting EVI2, whose exponential model showed R2... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Linear spectral mixing analysis; Rainfall simulator; Vegetation indices. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2018000300332 |
| |
|
|
| Drysdale, G.; Metternicht, G.. |
| This paper analyses the potential and limitations of airborne remote sensing systems for detecting crop growth variability and weed infestation within paddocks at specified capture times. The detection of areas of crop growth variability can help farmers become aware of regions within their paddock where they may be experiencing above and below average yields due to changes in soil or management conditions. For instance, the early detection of weed infestation within cereal crops is crucial for lessening their impact on the final yield. Transect sampling within a canola paddock of a broad acre agricultural property in the South West of Western Australia was conducted synchronous with the capture of 1m spatial resolution DMSI. The four individual bands... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: LAI; Remote sensing; Crop density; Vegetation indices; Weed mapping.; Crop Production/Industries. |
| Ano: 2003 |
URL: http://purl.umn.edu/24341 |
| |
|
|
| Alves,Ray Pinheiro; Couto Junior,Antonio Felipe; Martins,Eder de Souza; Nardoto,Gabriela Bielefeld. |
| Abstract The objective of this work was to evaluate the effect of soil carbon on landscape functioning of the Oxisols covering the plateaus of the Alto São Bartolomeu watershed, in the Cerrado (Brazilian savanna) region of Central Brazil. Soil organic carbon (SOC) concentration, carbon stocks, and some soil physical and chemical characteristics were determined at the 0-0.20-m depth on native and anthropogenic areas. Soils from cerrado stricto sensu patches were similar both physically and chemically, being affected by exchangeable Al3+ and by SOC concentrations, while anthropogenic matrices were affected by soil bulk density, pH, extractable P, and exchangeable Ca2+ and Mg2+. The estimate of spatial distribution of soil carbon better fitted had an adjusted... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Brazilian savanna; No-tillage; Oxisol; Pasture; Pedotransfer function; Vegetation indices. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2016000901241 |
| |
|
|
| Alba,Elisiane; Mello,Eliziane Pivotto; Marchesan,Juliana; Silva,Emanuel Araújo; Tramontina,Juliana; Pereira,Rudiney Soares. |
| Abstract: The objective of this work was to evaluate the use of Landsat 8/OLI images to differentiate the age and estimate the total volume of Pinus elliottii, in order to determine the applicability of these data in the planning and management of forest activity. Fifty-three sampling units were installed, and dendrometric variables of 9-and-10-year-old P. elliottii commercial stands were measured. The digital numbers of the image were converted into surface reflectance and, subsequently, vegetation indices were determined. Red and near-infrared reflectance values were used to differentiate the ages of the stands. Regression analysis of the spectral variables was used to estimate the total volume. Increase in age caused an addition in reflectance in the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Pinus elliottii; Remote sensing; Vegetation indices; Volume modeling.. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2017001101072 |
| |
|
| |
|
|
| Silva Júnior,Mário C. da; Pinto,Francisco de A. De C.; Queiroz,Daniel M. de; Vieira,Luciano B.; Resende,Ricardo C. de. |
| The aim of this study was to use digital images acquired by cameras attached to a helium balloon to detect variation of the nutritional status in Brachiaria decumbens. The treatments consisted of five doses of nitrogen (0, 50, 100, 150 e 200kg ha-1) with six replications each, evaluated in a completely randomized statistical design. A remote sensing system composed of digital cameras and microcomputers was used for image acquisition, and a helium balloon lifted the cameras to the heights of 15, 20, 25 and 30m. A portable chlorophyll meter and analyses of leaf nitrogen content were used to make comparisons with data obtained by the remote sensing system. Data was acquired in two phases, in different climatic conditions. At the end of each phase, dry matter... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Digital images; Vegetation indices; Nitrogen. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162013000500016 |
| |
| Registros recuperados: 14 | |
|
|
|
