Algorithm of Loss for Standing Tree Diffraction Based on a Wireless Sensor Network

Diffraction loss and the shadow of diffraction, which account for the growth of trees based on wireless sensors and automatic acquisition of environmental information, were presented to meet the requirements for a wireless sensor network in a forest. In order to reduce the complexities of estimating the signal strength and shadow when measuring standing tree, the concept of running-edge was also introduced to the propagation modeling in this project. Considering electromagnetic wave propagation, a diffraction model of standing tree in plantation is constructed using polygons to approximately take the place and approximation as approximate substitutes of for the circle. The mathematical model of standing tree diffraction is presented using the Fresnel-Kirchhoff and uniform geometrical theory of diffraction (UTD). Moreover, the expression of standing tree diffraction is derived, and the algorithm of the shadow is also discussed briefly. The results were then applied to the birch. Simulation and analysis show the validity of the proposed model.