Design, Implementation, and Deployment of TempMesh: A Wireless Mesh Network to Aggregate River-Temperature Data

As part of a restoration project designed to enhance Chinook salmon populations in the lower Yuba River, we sought to characterize river temperatures at micro-habitats scales relevant to juveniles. Given that temperatures vary more across the channel than they do longitudinally, temperature had to be assayed both along the length of a study reach as well as across the channel. These temperatures needed to be measured at least hourly in order to capture the totality of the diel fluctuations. It was necessary to sample for the full duration of juvenile residence in the lower Yuba River - a six-month period over the winter. Though it was desirable to design a system that could sample for at least a year to capture the totality of seasonal fluctuations. In this paper, we present the design, implementation and deployment of a wireless sensor network that was installed to monitor temperature data on the Lower Yuba River. The mesh network was implemented using nodes that contained a MSP430 chipset with a radio operating at 433 MHz. We describe the network architecture which included a network storage function to address intermittent link failures. We describe the event-based software architecture of the mesh network mode specifically in relation to energy optimization. We also give details of the deployment and provide measurement data.