REAL-TIME FOUR DIMENSIONAL DATA ASSIMILATION (RT-FDDA)
The Real-Time Four Dimensional Data Assimilation (RTFDDA) system is a computer-model that was originally developed by NCAR for producing analyses of current meteorological conditions and forecasts for U.S Army test ranges. Since then, the system has been adopted by other DoD and government agencies for support of special missions and for homeland-security applications.
RTFDDA focuses its computational resources on forecasting for specific geographic areas - not the entire continent, for example. This narrow focus enables the model to resolve a greater number of meteorological features while maintaining accuracy. The forecasting system can be deployed worldwide to address threats of a human or man-made nature. For example, RTFDDA has been used for counter-terrorism support for both the Athens and Salt Lake City Olympics and to forecast the movement of hazardous material potentially released into the atmosphere. The system was used by the Army to support operations in Afghanistan and Iraq and it provided superior forecasts of Hurricane Rita in September 2005. In summary, the system excels at representing the details of the day-to-day weather in urban areas, as well as the extreme weather associated with hurricanes and thunderstorms.
VARIATIONAL DOPPLER RADAR ASSIMILATION SYSTEM (VDRAS)
Developed by Jenny Sun and Andrew Crook (both MMM/RAL), it provides detailed and frequently updated information on wind, rain, and other real-time weather developments. VDRAS is the first real-time system to diagnose low-level wind and temperature over a wide region using four dimensional data assimilation of Doppler radar data.
VARIATIONAL LIDAR ASSIMILATION SYSTEM (VLAS)
A Doppler lidar variant of VDRAS. Also developed by Jenny and Andrew, this provides similar information as VDRAS, but at very high resolution, suitable for estimating winds at the neighborhood scale.
COMPUTATIONAL FLUID DYNAMICS (CFD)
A building-scale, computational fluid dynamics model to track the winds and movement of particles and chemicals around the Pentagon. Although this system is being developed by another organization, NCAR is testing its own version, developed by MMM’s Piotr Smolarkiewicz.
OPERATIONAL ALGORITHMS
Multiscale model blending
Source term reconstruction
Locating sources
Sensor placement
SENSORS
Standoff sensors (with subcats)
Point sensors (with subcats)