GPS navigation for precision farming

Precision farming, sometimes called site-specific agriculture, is a strategic task for agriculture: indeed it has the potential to reduce costs through more efficient and effective applications of crop inputs; it can also reduce environmental impacts by allowing farmers to apply inputs only where they are needed at the appropriate rate. Precision farming requires the use of new technologies, such as GPS, environmental sensors, satellites or aerial images and GIS to asses and understand variations. The present research deals with potentialities and limits of GPS for navigation in agricultural applications. GPS needs for farming applications are: − low cost in order to allow farmers to buy GPS technologies; − high precision in order to reduce the use of pesticides and fertilizers by means of an exact track. At first, static and kinematic tests have been performed, simulating the typical behaviour of an agricultural vehicle and using different kinds of GPS receivers and navigation softwares; the experimental results are presented: particularly, advantages and disadvantages of the popular Kalman filtering on trajectories are discussed. Starting from the analyses of the previous results, and taking into account the typical user requirements, a preliminary design for a new prototype has been done; particularly, both needed instrumentations and their costs and a proposal of a new navigation algorithm will be presented.