The Laser Environmental Effects Definition and Reference (LEEDR) was developed by CDE and aids in characterizing a location's atmosphere based on input parameters such as season, time of day, and relative humidity conditions. This worldwide surface to 100 km atmospheric characterization package enables the creation of profiles of temperature, pressure, water vapor content, optical turbulence, atmospheric particulates, and hydrometeors as they relate to layer transmission, and path and background radiance at any wavelength or wavelength band from the ultraviolet to radio frequencies. An air-to-ground, air-to-air, or ground-to-space cloud-free-line-of-sight (CFLOS) calculator for 415 land sites worldwide is included with the software package. LEEDR allows the export of the atmospheric characterizations for other Directed Energy Weapon (DEW) simulation codes, military or Department of Defense (DOD) mission planners, or non-military scientific research such as climate change impact studies.
To create the most realistic correlated, physically realizable vertical profiles LEEDR uses a novel approach to characterize the boundary layer. In general, LEEDR defines the well-mixed atmospheric boundary layer with a worldwide, probabilistic surface climatology based on season and time of day, and then computes the radiative transfer and propagation effects from the vertical profile of meteorological variables. This approach provides the capability to create atmospheric profiles that could actually occur or have actually occurred at a specific location. LEEDR also provides users the ability to input limited surface observation data as the driver of data profiles to create a more realistic profile. Additionally, a NOAA Operational Model Archive Distribution System (NOMADS) data feed has been incorporated to supply observations or real-time weather forecasts (out to 180 hours) for use in profile generation. The newest feature recently included in LEEDR v4.0 is an algorithm for refractive bending calculations, which allows it to model realistic paths while also considering attenuation parameters. This Path Bending tab provides actual path-to-target information depending on the Point-to-Point or Displaced Path geometry selection. These added functionalities further promote LEEDR's application to field operations and analysis.
The AFIT - Center for Directed Energy continuously performs research to improve LEEDR's ability to model and simulate transmission and path radiance through accurate and fast radiative transfer calculations. These calculations, which may be performed at line-by-line or across bands of the spectrum, are used to determine how much energy is released to space. This type of accurate analysis can help provide potential mission impacts to the DOD. Example current projects to improve LEEDR's modeling and simulation also involve research to verify and validate the optical properties of dust obscurants in the terahertz regime using a ThruVision TS5 imaging system and directly incorporate more forecast data feed sources.
Dr. Steven T. Fiorino, AFIT/CDE Director
Mr. Brannon Elmore, Contractor- Lead Software Developer
Jaclyn Schmidt, Contractor- LEEDR POC