By John T. M. Lyles
The Fort Stanton Cave Study Project, in collaboration with the Roswell Field Office of the Bureau of Land Management, is developing a distributed communication network for data, that will be tested in a small-scale prototype configuration in 2020. The ultimate goal is to establish a quasi-real time sensor network to measure air conditions such as temperature, movement, direction, and CO2 content, and measure similar water conditions in the intermittent Snowy River stream channel from the closest point at Turtle Junction back to the surface and to a nearby facility. This is through varying passage dimensions and numerous bends and crawls, for a total of about 2 miles. Data throughput is not high, as this system is intended to be extremely low power using numerous nodes to relay data similar to a mesh network. A plethora of hardware/software choices are commercially available in the Internet of Things marketplace. The challenge has been in selecting the best design for the uncommon attributes of cave environments. Non-licensed UHF [ultra high frequency] frequencies at ~915 MHz [megahertz] have been chosen based on range, antenna size, propagation characteristics of tunnels, and availability of nodes. A hardware variation of the Zigbee standard called Xbee is likely to be used, using DigiMesh protocol. It is optimized for battery life as nodes will remain asleep with little power consumption, waking up at predetermined times to pass traffic.