Novel Characterization Measurements and Meteorological-Driven Modeling of Turbulence and Refraction in the Lower Atmosphere for Directed Energy Applications
Abstract
Novel Characterization Measurements and Meteorological-Driven Modeling of Turbulence and Refraction in the Lower Atmosphere for Directed Energy ApplicationsAbstract: Attempts began decades ago to develop accurate models for the high energy laser (HEL) directed energy (DE) community to quantify and predict the impact of atmospheric turbulence and refractivity effects on beam and image propagation in the lower atmosphere. This modeling work continues today but with only limited success because of challenges that arise fo"r two majorreasons. First, surface layer atmospheric effects are difficult to describe mathematically because they result from turb"ulence that is not fully developed and hence not well defined in a statistical sense. This means the propagation path commonly exhib"its anisotropic, inhomogeneous and nonstationary characteristics. Second, there is a lack of comprehensive data for turbulence and r"efractivity along diverse propagation paths. The development of accurate surface layeratmospheric optical models requires turbulence and refractivity measurements inside the 3D (volume) surface layer perhaps over several square miles and up to 100-m elevation ~ data that cannot be obtained using conventional atmospheric sensing techniques. To address and potentially resolve the major challenges in understanding the surface layer atmospheric opticseffects and to develop mathematical and numerical models capable for accura"te performanceprediction of future HEL laser weapon systems, the collaborative research team comprised of theacademic institutions"" of New Mexico State University, the Air Force Institute of Technology, and the University of Dayton proposes comprehensive studies" that include the following specific objectives and tasks: (1) development of novel atmospheric sensing techniques focused on 3D cha"racterization of atmospheric refractive index fields (turbulence and refractivity) near theground, (2) field measurements and data" collection of major atmospheric and meteorologicalcharacteristics at different sites with different terrain and under various weat"her conditions, (3) extensive numerical simulation, such as fluid dynamics based approaches of atmospheric optics processes near the"" surface layer for selected measurements and field sites, (4) comparative analysis of field measurement data and high performance si""mulation results, and (5) development of a physics based set of models for characterization of atmospheric optics effectsapplicable"" for predictive performance analysis of HEL DE system operation at low elevation engagement scenarios. In the proposed effort, the t"eam offers the development of new sensing techniques that include target-in-the-loop atmospheric sensing using flying drones caring" small retro-targets, turbulence and refractivity sensing using time-lapse imaging, and high spatial and temporal resolution turbule""nce measurements with Hartmann and multi-aperture wavefront sensors. Field measurements are planned at Dayton, OH and Las Cruces, NM"", with joint experimental campaigns at White Sands Missile Range, NM and/or NSWC-Crane, IN. Computational fluid dynamics simulations" have shown great promise for modeling the realistic 3D atmospheric optical turbulence and refractivity characteristics. This approach will be appliedto scenarios that are encountered in the field measurements. The results will be applied toimprove analytic para"metric models, such as the modified Tatarskii predictive model, the HELEEOS and PITBUL models from AFIT, as well as numerical wave o"ptics simulation techniques.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- May 05, 2017
- Source ID
- N000141712535
Entities
People
- David Voelz
Organizations
- New Mexico State University
- Office of Naval Research
- United States Navy