From Soil to the Cloud: Permanent Wireless Underground Sensors for Autonomous Irrigation.

The recent developments in low-power wireless communication, distributed sensing, and networking allow sensor networks to be deployed in places where no computer has gone before. Wireless underground sensor networks are an emerging type of sensor networks, where sensors are located under the ground and communicate through soil. Their applications involve precision agriculture, environment monitoring, and border patrol. Due to the significant impacts of the soil dynamics on communication, unique challenges exist for the development of networking solutions in this media. The recent developments in wireless underground networking and its applications to precision agriculture control will be described. Nebraska Underground Sensing and Precision Agriculture Testbed at the University of Nebraska-Lincoln and recent experiments with center pivot irrigation system deployments in this testbed will be discussed. The underground communication system, developed in the Cyber-physical Networking (CPN) Laboratory at the University of Nebraska-Lincoln, is tailored to mitigate the adverse effects of soil on underground communication. An online connection is established with the CPN underground sensor network testbed that is located at Clay Center, Nebraska. The underground sensor network testbed consists of a network of underground communication systems equipped with soil moisture sensors and a mobile data harvesting unit equipped with cellular communication capabilities. Real-time soil moisture data delivery is demonstrated.