T&E Programs

New Test Range Capabilities LIDAR for Turbulence and AerosolS

Electro-Optical system performance on test ranges is degraded by both turbulence and aerosols. The LIDAR system meets a long-standing need for turbulence profiles along laser beam paths. It also provides profiles of aerosol concentration. In field tests, the turbulence LIDAR will allow estimation of turbulence-induced degradations, such as laser beam spread, wander, jitter, and scintillation. The LIDAR can also be used to create databases of turbulence profiles at test ranges.

• Background: Optical turbulence can cause major degradations to HEL beams propagating on atmospheric paths. Turbulence is characterized by C_n², the index of refraction structure characteristic.
• Knowledge of the C_n² profile along the path would allow these degradations to be quantified and possibly corrected (via adaptive optics).
• Currently C_n² can only be measured at points or on fixed paths. These measurements do not coincide with typical laser beam paths.
• A DIM LIDAR combines astronomical DIM techniques with LIDAR technology to obtain C_n² profiles along or adjacent to the laser beam path.
• The C_n² profile can be used to calculate the atmospheric coherence parameter ( r₀ ), the isoplanatic angle ( θ₀ ), and other turbulence parameters.
• The LIDAR also records profiles of aerosol extinction, which causes loss of beam power and contributes to thermal blooming.

The turbulence LIDAR was developed by the GTRI LIDAR Team. The brassboard version successfully completed verification testing in December 2007 and remains at HELSTF as a permanent facility instrument.

Acknowledgement: The project described here was funded under the DTRMC DE T&E/S&T Program, Minh Vuong, Executing Agent

For more information:

Gary Gimmestad
Electro-Optical Systems Laboratory
Phone: 404-407-6029  
Email: gary.gimmestad@gtri.gatech.edu

Last Updated March 11, 2008

Home | Events | T&E Programs | T&E Tools | Education | About TEREC | Contact

Send all questions and comments to terec@gatech.edu | Copyright © 2007 www.terec.gatech.edu
Notwithstanding any language to the contrary, nothing contained herein constitutes nor is intended to constitute an offer, inducement, promise, or contract of any kind. The data contained herein is for informational purposes only and is not represented to be error free. Any links to non-Georgia Tech information are provided as a courtesy. They are not intended to nor do they constitute an endorsement by the Georgia Institute of Technology of the linked materials.