Test of wireless sensor network radio frequency signal propagation based on different node deployments in citrus orchards

In this paper, for configuring WSN system architecture and node deployment in citrus orchards, relationship between wireless sensor network (WSN) radio frequency (RF) signal strength attenuation and the corresponding influential factors was studied based on radio wave propagation characteristics. In this study, a carrier frequency being 433MHz was selected and the attenuation of radio wave in citrus orchards was analyzed based on continuous radio waves in the circumstance of different combinations of impact factors including plant depths, antenna heights, communication distances etc. Additionally, a WSN RF signal strength linear model objectively feasible in citrus orchards was built, with the related determination coefficients for fitting-curves ranging from 0.797 to 0.980, in order to ensure the possibility of predicting the tendency of receive signal strength attenuation with the existence of two factors, RF propagation distance and environmental propagation factor. As a consequence, a distributive chart of the best antenna height indicating the combination of different plant depths, antenna heights and communication distance variations was obtained, possibly providing good guidance for WSN system configuration and node deployment in citrus orchards.