Modelagem de propagação para redes de sensores sem fios aplicadas à viticultura.

Abstract

The technologies of precision agriculture permit the management of natural resources for a sustainable development of the environment, as well as the reduction of costs and an increase in the production margin of profit. In this context the wireless sensor networks are presented as a solution to gather soil and environment information, in large distributed areas. The Sao Francisco Valley region in the Northeast of Brazil has as main economic activity the irrigated fruit production, and is one of the major agricultural regions of the Country. Grape plantations receive large investments and provide good financial return. However, the region still lacks electronic sensing systems to extract adequate information from plantations. Considering these facts, this dissertation presents a study of path loss in grape plantations for a 2.4 GHz operating frequency. In order to determine the position of the sensor nodes, various environmental factors, that influence the intensity of the received signal by a transceiver, must be considered. The analysis of the communication channel presented in this dissertation provides subsidy for the network designer to determine the optimal positions to place the sensors to achieve greater coverage area. The main propagation phenomena were identified and interpreted for the studied environment. Also, the parameter adjustment of the propagation models from the literature was performed. XBee-PRO ZB S2B devices were used to measure the signal intensity.