Abstract :
• Each element of a wireless sensor network in a grain silo must be capable of relaying its 3D position coordinates to the central gateway either directly via line of sight, or indirectly through neighbouring elements. • For this purpose, a spherical iso-phase positioning system is proposed for the networked wireless sensors in wheat based on the classic ‘time of flight’ trilateration approach. • An UWB bi-phase pulsed signal excitation format will be adopted here in order to mitigate the anticipated multi-path reflections from the silo vessel wall and from neighbouring sensors.