Changes of data sampling procedure to avoid energy and data losses during microclimates monitoring with wireless sensor networks.

Wireless sensor networks are gaining importance in agricultural applications, such as monitoring crops microclimates. Precision agriculture is one of the areas that can most benefit from this technology in the sense that wireless sensors networks allow data collection with high resolution, enabling better decision making. Such networks have restrictions on their deployment in a real environment, for example, on energy. Thus, several studies have been conducted in order to optimize the use of this technology. Depending on the application, it is desirable that the available energy on sensor nodes batteries allows operation for months or even years. One proposed solution to extend the lifetime of sensor nodes, so as to avoid unnecessary data collection, is the implementation of a routing protocol that allows a differentiated data sampling. An application that can benefit from this approach is vineyard microclimates monitoring, which is very important to monitor temperature and reIative humidity, and can apply precision agriculture techniques to the crop. Thus, in the program to be installed into sensor nodes, rules for data collection are defined, so that the value collected by the sensor at a given time is in the rule that defines normal conditions, the rate of sampling data used will be higher; however, when the value collected by the sensor is out ofthis rule, the sampling rate will automatically be reprogrammed to a higher value. This differentiated data collection allows savings in power consumption under normal conditions, and generates less data to be analyzed. Keywords: Wireless sensor network, microclimates monitoring, vineyards differentiated data samplin

Um estudo da variabilidade microclimática em um vinhedo cultivado sob cobertura plástica mediante o uso de uma rede de sensores sem fio.

As variáveis ambientais em um cultivo protegido experimentam algumas alterações espaciais e temporais. Para conhecer melhor o comportamento dessas variáveis, e dessa forma, atuar com mais eficácia na cultura, aplicando os conceitos da agricultura de precisão, podem-se utilizar novas tecnologias que forneçam maior suporte à melhor tomada de decisões. Apresenta-se uma avaliação da variabilidade microclimática dentro de um vinhedo cultivado sob cobertura plástica, fazendo uso de uma Rede de Sensores sem Fio. Os resultados mostram a existência da variabilidade microclimática dentro do vinhedo, tanto a diferentes alturas da videira, como espacialmente, a qual é maior durante o dia do que durante a noite. Após a avaliação da utilização dessa rede em campo, foram percebidos alguns desafios a serem considerados na tentativa de melhorar o desempenho da mesma, como a incorporação de novos tipos de sensores. Porém, pelas vantagens observadas do uso desta tecnologia em relação a um sistema de monitoramento convencional, considera-se promissora a sua adoção na viticultura brasileira. ABSTRACT: Environmental variables in a protected cultivation experiment some spatial e temporal changes. For a better understanding of the behavior of these variables, and thus, to act more efficiently into the crops, applying precision agriculture concepts, new technologies that help a better decisionmaking can be incorporated. An evaluation of microclimate variability within a vineyard cultivated under plastic overhead cover, using a wireless sensor network, is presented. The existence of microclimatic variability at different heights of the vine, and spatially, within the vineyard is shown, which is greater during the day than at night. From the evaluation of the network to the crop, challenges were perceived and are considered in an attempt to improve network performance, such as the incorporation of new types of sensors. However, due to the benefits observed with the use of this technology as compared to a conventional monitoring system, its adoption in Brazilian viticulture is considered promissory