Propagation variability assessments of ship defense HEL and HPM performance in worldwide maritime boundary layer environments at wavelengths of 1.0642 μm, 2.141 μm, 3.16 mm and 12.2 cm

Abstract

This study quantifies the variability in ship defense high energy laser (HEL) and high power microwave (HPM) performance due to atmospheric effects in the marine boundary layer relative to a commonly defined standard atmosphere. The atmosphere effects are defined using the worldwide probabilistic climatic database available in the High Energy Laser End-to-End Operational Simulation (HELEEOS) model. The expected propagation performance is assessed at 4 wavelengths (1.0642 μm, 2.141 μm, 3.16 mm, and 12.2 cm) across the world's oceans and mapped on a 1° × 1° grid. Scenarios evaluated are primarily near-surface and horizontal over ranges up to 9000 meters in which anticipated clear air aerosols and thin layers of fog, light rain, and various cloud types occur. Seasonal (summer and winter) and boundary layer variations for a range of relative humidity percentile conditions are considered to determine optimum employment techniques to exploit or defeat the environmental conditions. Optical turbulence impacts and numerous atmospheric particulate/hydrometeor distributions are evaluated based on their wavelength-dependent scattering and absorption effects on HEL/HPM engagement. HELEEOS includes a fast-calculating, first principles, worldwide surface to 100 km, atmospheric propagation and characterization package. This package enables the creation of profiles of temperature, pressure, water vapor content, optical turbulence, atmospheric particulates and hydrometeors as they relate to line-by-line layer transmission, path and background radiance at wavelengths from the ultraviolet to radio frequencies. Physics-based cloud and precipitation characterizations are coupled with physically correct temperature and moisture vertical lapse rates to create realistic atmospheric boundary layer effects. HELEEOS characterizes maritime aerosol environments using the Advanced Navy Aerosol Model (ANAM) or various representations of maritime particulates from the Global Aerosol Dataset (GADS). In the lowest 50 m, HELEEOS defines maritime optical turbulence with the Navy Surface Layer Optical Turbulence (NSLOT) model.