Solar node and gateway wireless system functions in record breaking polar vortex outbreak of February 2021

Authors: Evett, Steven - Steve; Thompson, Alondra; Schomberg, Harry; ANDRADE, MANUEL - University Of Nevada; ANDERSON, JOHN - Acclima, Inc

Submitted to: Agrosystems, Geosciences & Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/14/2021
Publication Date: 10/9/2021
Citation: Evett, S.R., Thompson, A.I., Schomberg, H.H., Andrade, M.A., Anderson, J. 2021. Solar node and gateway wireless system functions in record breaking polar vortex outbreak of February 2021. Agrosystems, Geosciences & Environment. 4(4). Article e20193. https://doi.org/10.1002/agg2.20193.
DOI: https://doi.org/10.1002/agg2.20193

Interpretive Summary: Center pivot irrigation systems are now used on more than 55% of U.S. irrigated lands and all modern systems are capable of some level of variable rate irrigation (VRI) – applying more or less water in different areas of the field as required for best crop growth and yield. Yet, user-friendly decision support systems for VRI are lacking, in part because the sensor systems needed to inform decision support are often too expensive and inflexible to be used for irrigation management. USDA ARS scientists developed a low-cost, solar-powered, wireless system for reading sensors that determine soil water and plant water status, the two key data needed for VRI management. The scientists then transferred this technology to an industry partner who delivered a commercial version. Reliability of the system was severely tested during the February 2021 polar vortex outbreak that brought temperatures down to -21 degrees F in the Texas Panhandle. Readings from 36 soil water sensors continued to be gathered and transferred to the internet for use in irrigation decision support during the cold temperatures and two snowstorms, proving the reliability of the system even in extreme conditions.

Technical Abstract: Advances in environmental and agricultural management are increasingly enabled by unattended data acquisition using internet-of-things (IOT) approaches. These approaches combine advanced sensors and wireless data transmission to automatically and transparently convey field data to the internet. Users, either human or machine, then can access and act upon the data from nearly anywhere in the world. Particularly in the case of machines automatically acting on the data, robustness, reliability and accuracy of data are crucial to preventing unintended outcomes of machine operations and continued supply of key services. Low cost, low power and solar-powered systems are important to enable market entry of advanced decision support systems based on IOT data acquisition approaches. The polar vortex outbreak of February 2021 in the central United States provided an extreme test of a solar-powered, low-cost node and gateway system for automatic data acquisition and telemetry to the internet over the cellular telephone network. The system, codesigned by USDA ARS and cooperative research and development agreement (CRADA) partner Acclima, Inc., performed admirably despite air temperatures reaching a minimum of -24°C, temperatures <0°C for eight days and <7°C for six days, two snowstorms and overcast conditions. The six nodes, gateway and 36 sensors continued to function reliably with a data transmission failure rate of <2 in 10,000, and even though the Li-Ion batteries could not be recharged for seven days due to temperatures <5°C. The system reports geographic position of each node and gateway, model numbers and firmware versions of all equipment, including sensors, and individual sensor elevations relative to a reference surface, affording data self-identification for unfettered use by remote systems.