Global Cloud-Free Line-of-Sight (CFLOS) Characterizations Using Numerical Weather Prediction Data

The ability to predict cloud-free line-of-sight (CFLOS) continues to be a critically important parameter for Department of Defense operations and remote sensing applications. Current CFLOS climatologies are available for a limited number of worldwide sites, providing ground-to-space probabilities that do not account for elevation and azimuthal variations. The Air Force Institute of Technology’s Center for Directed Energy (AFIT CDE) has developed a robust simulation technique leveraging years’ worth of numerical weather prediction (NWP) model data and AFIT CDE’s realistic sky characterization algorithms to define NWP-inferred cloud and precipitation layers of various types. The resulting analysis yields CFLOS probabilities for any worldwide location, including littoral and over-ocean sites. Recent optimizations can quickly evaluate 10 years of NWP data and generate new CFLOS climatologies for various worldwide locations, times of day, and view angles considering azimuthal variations.