A Two-Tier Wireless Sensor Network Infrastructure for Large-Scale Real-Time Groundwater Monitoring

In this paper, we describe the design, implementation and deployment details of a two-tier real-time environmental monitoring network in Nebraska. Our state-wide sensor network infrastructure uses typical Wireless Sensor Network (WSN) structure at tier-two to conduct dynamic sensing tasks with high resolution and flexibility. The satellite communication technology is used at tier-one to provide reliable and low-cost long-haul connectivity between each local WSN and the central base station. By the end of 2009, the entire tier-one infrastructure has been designed and deployed to provide state-wide wireless connectivity for 54 monitoring sites equipped with 1-4 water level transducers. A data and network management framework has also been developed to enable the remote network retasking and network performance analysis from a central base station. The network web portal offers integrated real-time and historical groundwater data to worldwide users. The deployed infrastructure will serve as the prototype network to expedite the commercial adoption of large-scale WSN design for long-term environmental monitoring applications.