UHF wireless communication channel in a tree canopy

A wireless sensor network has played an important role in various applications including agriculture where it is essential in quality control of fruit production. Microwave sensors have been installed on fruits to monitor their ripeness and signals corresponding to the level of ripeness were sent from the fruits on a tree to the tree node on that tree and then to the master node to warn growers to harvest at the appropriate time. For an effective design of a wireless communication system in a tree canopy, channel characteristics are highly desirable. The works on propagation through foliages have been comprehensively reviewed but none of them were for propagation channel in a tree canopy. Hence, a propagation channel in a tree canopy is presented experimentally in this paper.