Research Summaries

Back Analysis of Propagation of Lasers at Various Wavelengths and Power Levels Based on Atmospheric Conditions

Fiscal Year 2019
Division Graduate School of Engineering & Applied Science
Department Physics
Investigator(s) Cohn, Keith R.
Blau, Joseph A.
Sponsor Naval Sea Systems Command (Navy)
Summary As the USN moves forward with plans to deploy directed energy (DE) weapons to the fleet, further research on atmospheric effects is needed. This will help guide the Navy in developing tactics for DE weapons in various scenarios. The ultimate goal is real-time atmospheric characterization to inform operators and guide the use of HEL weapons.
An important atmospheric effect is ship-induced optical turbulence. Solar heating of the ship’s deck during the day, and the complex airflow around the superstructure, can induce significant turbulence in the immediate vicinity of the laser beam director. Recently we conducted an experiment to study this effect onboard the USS Spruance. We measured various atmospheric parameters including air and deck temperatures, wind speed, and solar flux, at multiple locations while in port and underway. We are currently analyzing this data to determine levels of turbulence at various locations and heights above the ship's deck, and correlations with other measured parameters.
Over the course of this project, we will continue to analyze the many gigabytes of data that we obtained from this experiment. We will use laser propagation models to estimate the effect of the measured turbulence levels on HEL weapon performance for various atmospheric conditions and engagement scenarios.
We will also conduct further experiments, both at NPS and onboard naval vessels. These experiments will provide a more complete picture of the optical turbulence above the ship’s deck in a variety of operational and weather conditions. We will also study ideas for mitigating ship-induced turbulence, including the use of different deck materials and colors in the vicinity of the beam director.
Deliverables from this project will include monthly written reports, student theses, and presentations to the sponsor.
Keywords Directed Energy high energy lasers
Publications Publications, theses (not shown) and data repositories will be added to the portal record when information is available in FAIRS and brought back to the portal
Data Publications, theses (not shown) and data repositories will be added to the portal record when information is available in FAIRS and brought back to the portal