CASA (Center for Collaborative Adaptive Sensing of the Atmosphere)
NSSL is participating in an NSF-sponsored Engineering Research Center called the Center for Collaborative Adaptive Sensing of the Atmosphere (CASA) to explore sensing the lower atmosphere with a network of many short-wavelength (3cm) radars. These smaller and less expensive radars will be spaced much closer together than those in the current operational radar network to provide data in these blind spots caused by the curvature of the earth. CASA will also employ a new observation methodology termed DCAS (Distributed Collaborative Adaptive Sensing), that will operate the network of radars collaboratively and adapt them to changing atmospheric conditions and the needs of various end users. In short, "distributed:" having multiple radars available to scan an area; "collaborative:" where there is overlap, neighboring radars will scan an area if the main radar is busy scanning something else, and "adaptive:" the radars will change scanning strategy based on the weather and user needs. The system of radars that are part of the Oklahoma testbed (called Network Radars or NetRAD) are spaced 30km from each other and are one-fifth the size of a NEXRAD radar. Assembly and integration of the radar transceivers, pedestals, radomes, node-level computation and communication electronics of the radars took place at NSSL. In March, 2006, the four NetRAD radars were installed in Rush Springs, Lawton, Cyril, and Chickasha,. OK. NSSL's WDSS-II will ingest and process NetRAD data for detection algorithms. The goal of the Oklahoma Test Bed is to demonstrate DCAS concepts for high temporal and spatial resolution sensing of winds in the lower atmosphere and detecting, tracking, and predicting severe storms, especially tornadoes.
How do DCAS systems work?
The first generation DCAS systems will use low-cost, small radars deployed on cell phone towers or other structures, and collaboratively detect the region of the lower atmosphere currently below radar range. Deployment of the DCAS network will involve tens, hundreds, or even thousands of interacting radar nodes deployed in heavy population areas, in areas particularly prone to wind hazards or flash floods, in mountain valleys, or in other areas where the observation of low-level meteorological phenomena is critical.
DCAS benefits
- Significant reductions in tornado false-alarms
- Improve precipitation estimates for flood prediction
- Detection of humidity and temperature variables
- A vastly superior understanding of how winds carry chemical, radiological or biological hazards
- All of these will save lives and reduce property losses
Scalable prototype testbeds will be implemented in Oklahoma, Houston, and Puerto Rico.
