Mini-RWIS Pilot Project

Abstract

Campbell Scientific in partnership with ADOT&PF successfully demonstrated the use of a low-power, low-cost, small-footprint, mini-RWIS concept in Alaska that could reliably deliver atmospheric and road temperature data as well as camera images year-round. The project originally was conceived to demonstrate eight mini-RWIS stations. ADOT&PF personnel performed site selection. Of the eight mini-RWIS initially conceived for this demonstration project seven mini-RWIS stations were successfully deployed at selected sites in DOT Northern and South-Central regions. The eighth station was incorporated into a University of Alaska project at Atigun Pass that was designed to provide data, forecasting and warning for avalanche risks on the Dalton Highway. The system utilized multiple cameras, blowing snow sensors, as well as other atmospheric sensors on a solar panel/battery system. This station at Atigun Pass should be considered a step above the mini-RWIS concept and is, by far, the northern-most advanced RWIS station deployed in the state of Alaska providing data in an area where the climate conditions are extreme. As such, the station requirements were designed to withstand, high winds, temperatures below -40oF, the potential for rime ice, two months without sunlight, and lack of cellular connectivity. Consequently, the location challenged the equipment. Campbell Scientific initially shipped all equipment to Alaska in the spring of 2019 to be cold chamber tested at the University of Alaska Fairbanks (UAF), then installed in the field prior to the winter season. Cold chamber testing was successfully accomplished, however, due to a variety of delays these stations were not installed prior to the 2019/2020 winter season. In March of 2020, the global COVID-19 pandemic prevented Campbell Scientific personnel from traveling and installing stations during the summer of 2020. Instead, Campbell Scientific reached out to a long-time user of CS equipment, Michael Lilly of Geo-Watersheds Scientific (GWS), in Fairbanks, AK. Michael and his team have decades of experience in the design of low-power data acquisition systems and networks (including power system design, programming, installation, and maintenance) with specialization in remote hydrological and meteorological monitoring stations. The GWS team set out to understand the needs of the project and immediately became fully invested. As a result, the mini-RWIS system design went through a modification process per the recommendations of the GWS team. Campbell Scientific work with GWS to affect the following changes to the mini-RWIS: • Expansion of battery bank considering the long Alaskan winters • Addition of CH200 regulator for the purpose of gathering critical information on the performance of the power system. • Addition of a fiberglass enclosure for the purpose of protecting cables from wildlife during winter months when food sources are depleted. • Reprogramming of dataloggers to meet project goals • Configuration of CCFC camera for optimization of power requirements. GWS was contracted by CSI with approval from ADOT&PF (Contract # 2520H016 Amendment #1) to utilize GWS’ services for installation of two stations during the winter of 2020/2021. ADOT&PF personnel also installed one station during the winter of 2020/2021. Campbell Scientific personnel traveled to Alaska for two weeks during September of 2021 to install the remaining four mini-RWIS stations prior to the 2021/2022 winter season. Maintenance was performed on the three previously installed stations during that trip. Project update meetings were held between CSI, ADOT&PF, UAF, and GWS prior to the 2021/2022 winter season with additional performance review meetings in January 2022 to discuss station performance. CSI personnel additionally traveled to Alaska during July 2022 to visit project stakeholders in Anchorage and Fairbanks and to visit each of the seven mini-RWIS stations to perform general maintenance. In total seven mini-RWIS stations were installed between the northern and central regions in Alaska. The equipment (datalogger, sensors, power system, enclosures, etc.) from the eighth mini-RWIS station, with the support of ADOT&PF, was repurposed for a project being done by UAF personnel with the support of GWS. The CR300 datalogger (embedded in the mini-RWIS stations) was upgraded to the higher capacity CR1000X due to the need for additional sensor inputs, and additional sensors were used including two blowing snow sensors and an additional wind speed and direction sensor, an extreme-cold temperature sensor and snow depth, and snow temperature profile sensors. The seven standard mini-RWIS stations were assessed based on the performance of the atmospheric sensor data (including wind speed and direction, air temperature and relative humidity, and road surface temperature), reliable delivery of camera images, power performance, and cellular communication performance. The performance of the advanced winter-hazards RWIS was performed by the Atigun Pass project. Throughout the study period atmospheric data proved to be within an acceptable and expected range, was reliable and was recorded without failures. Camera images were reliable and delivered in a timely manner over the cellular network. The power performance proved to be very robust and more than sufficient for the power needs of the mini-RWIS stations. Cellular communications proved reliable. Several minor instances of loss of cellular connectivity were encountered but cellular connection was regained quickly and self-corrected.