Virtual Atmospheric Dispersion Field Testing

Virtual Threat Response Emulation and Analysis Testbed (VTHREAT)
Figure 1. Virtual Threat Response Emulation and Analysis Testbed (VTHREAT)

In order to more robustly test and evaluate the evolving VIRSA system, RAL has developed the Virtual Threat Response Emulation and Analysis Testbed (VTHREAT), enabling simulation of physically realistic hazardous release scenarios, placement of material and meteorological sensors, and extraction of the resulting synthetic sensor readings (Fig. 1).  VTHREAT utilizes research grade Numerical Weather Prediction (NWP) and Atmospheric Transport and Dispersion (AT&D) models to generate high-resolution realizations of the turbulent atmospheric boundary layer and the resulting turbulent transport of materials released in the synthetic environment.  More specifically, VTHREAT is currently leveraging the Large Eddy Simulation (LES) capabilities provided by the Weather and Research Forecast (WRF) NWP model, combined with continued advancements being made with the NCAR Lagrangian Particle Dispersion Model (LPDM).  The resulting environmental simulations can then be sampled utilizing a variety of material and meteorological sensor models, which emulate the operating characteristics of the sensing modality. These tools have been incorporated into a consolidated desktop software application, which allows a user to load virtual test simulations, visualize the 4-dimensional environment, place material and meteorological sensors within that environment, and save the sensor readings for later analysis or as input to downstream sensor information systems.  The GUI architecture is currently based on the National Aeronautics and Space Administration (NASA) World Wind Java Geospatial Visualization Platform, which provides access to a variety of external web map server (WMS) services and datasets, and an immersive display environment for data.

Accomplishments in 2017

We are developing a new LES model, called FastEddy, on a Graphics Processing Unit (GPU), to allow for a much faster generation of virtual data sets.

FY2018 Plans

Continue the development of FastEddy, including the ability to simulate complex topography, urban environments, and coupling of the micro and mesoscales.