Engineered System: Detecting Low-altitude Extreme Weather Threats

Today's weather forecasting and warning systems utilize data from high-power, long-range radars that have limited ability to observe the lower part of the atmosphere because of the Earth's curvature. This means that meteorological conditions in the lower troposphere are under-sampled, leaving us with precious little predicting and detecting capability where most weather forms.

CASA, the center for Collaborative Adaptive Sensing of the Atmosphere, is an ERC headquartered at the University of Massachusetts-Amherst. It aims to overcome the effects of the Earth's curvature and obstructions such as mountains and buildings by deploying low-cost networks of Doppler radars that operate at short range. Installed on existing rooftops and cell towers just a few miles apart, these small radars will communicate with one another and adjust their sensing modes in response to quickly changing weather and user needs—a dramatic change from current technologies. Up-to-the-second radar information will then be transmitted to the people and organizations that make critical decisions about the weather.

CASA's new approach is called DCAS, Distributed Collaborative Adaptive Sensing. Distributed refers to the use of large numbers of small radars, appropriately spaced to overcome the Earth-curvature blockage that limits current approaches. The radars operate collaboratively within a dynamic information technology infrastructure, adapting to changing atmospheric conditions in a manner that meets competing end user needs. This network comprises an excellent example of an engineered system.

CASA has implemented scalable prototype test beds in Oklahoma and Puerto Rico, in collaboration with industry and government partners and users of weather data such as the Dallas-Ft. Worth regional government. The test bed in Oklahoma has already been used to assist in real-time forecasting of tornadoes and has saved lives.