This Small Business Technology Transfer Phase I project will develop a new Present Weather Sensor (PWS). The impact of this project will be felt in the transportation sector where, annually, 1.4 million traffic accidents are caused by weather at an estimated cost to the nation of $42 billion. Knowing whether freezing rain or snow is present greatly influences how Departments of Transportation approach anti-icing, plowing, and road closure operations. State budgets for road weather safety run in the tens of millions and an estimated ten dollars is saved for every dollar spent on improving weather systems. There is a federal push for improvements to the 2499 Roadside Weather Information Systems (RWISs) nationwide. Unfortunately, no existing Present Weather Sensor has the capacity to accurately assess precipitation type. The new PWS will offer a highly sophisticated and flexible instrument for determination of hydrometeor form that offers broad utility for improving transportation safety. Assuming widespread implementation of the new PWS in the RWIS network, the anticipated domestic market size is in excess of $10 million. Present Weather Sensor devices are widely deployed by weather networks used by the scientific, weather monitoring, agricultural, communications, and transportation safety communities. A key capacity of any PWS is an ability to automatically distinguish hydrometeor types, including snow, rain, sleet, and hail. However, PWS sensors are known to be unreliable, particularly around the freezing point where precipitation related damages tend to be greatest. Current PWS instruments only measure the attenuation of one or two radiation beams; in this case, questionable and fallible assumptions are required to obtain hydrometeor phase and form. For this Phase I project, new high-speed photographic imaging techniques will be used to quantitatively diagnose the quantity of liquid in hydrometeors, working on the basis that the presence of liquid is characterized by surface smoothness and differential visible/near-IR absorption. The result of this study will be a prototype PWS that can achieve on-the-fly diagnoses of hydrometeor size, shape, and phase.
