Low levels of shade and climate change adaptation of Arabica coffee in southeastern Brazil.

Coffee is one of the most consumed beverages in the world, and its international market has been growing for many years. Unfortunately, the Brazilian coffee production is threatened by high temperatures projected by climate change models. We evaluated three schemes of low levels of shade, which avoid the loss of production, as a strategy to adapt coffee to possible climate change. Additionally, as field measurements are expensive and often difficult to implement, we used numerical simulation to complement the evaluation. The microclimate simulator software Envi-met is a computer program often used to simulate urban environments, and we tested it on agriculture design. We verified that the shaded schemes assessed in the field decreased the air temperature in 0.6 °C in the studied period and reduced other possible climate stressors such as wind speed, radiation and raised air humidity in the dry period. Envi-met described the studied meteorological variable cycle very well, showing that combining numerical modelling and field research may be an important tool for planning the adaptation of the coffee sector to possible climate change, allowing growers choose a proper technique for their regions and environmental conditions. Finally, we highlighted the importance of planning the shade scheme on coffee areas in an interdisciplinary approach, including local climate evaluation to achieve a balance between temperature attenuation and production.

In-flight absolute calibration of the CBERS-2 CCD sensor data

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.

Desde o início da distribuição de imagens dos sensores do satélite CBERS-2 (China-Brazil Earth Resources Satellite) por parte do Instituto Nacional de Pesquisas Espaciais (INPE), a comunidade de usuários solicitava informação sobre a conversão dos números digitais em valores físicos (radiância ou reflectância). Este artigo descreve os principais passos adotados no cálculo dos coeficientes de calibração absoluta para as imagens disponibilizadas no nível 2 de correção (correções radiométrica e geométrica) da câmera CBERS-2 CCD, considerando o método baseado na reflectância de uma superfície de referência. São apresentados também alguns resultados da avaliação preliminar da aplicação desses coeficientes na conversão mencionada.

In-flight absolute calibration of the CBERS-2 CCD sensor data.

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.