A Technique for Estimating the Strength of Turbulence and Inner Scale along an Optical Propagation Path

Award Information
Agency: Department of Defense
Branch: Air Force
Contract: FA9451-07-C-0032
Agency Tracking Number: F061-009-2005
Amount: $749,966.00
Phase: Phase II
Program: SBIR
Awards Year: 2007
Solicitation Year: 2006
Solicitation Topic Code: AF06-009
Solicitation Number: 2006.1
Small Business Information
G A TYLER ASSOC., INC.
1341 South Sunkist Street, Anaheim, CA, 92806
DUNS: 801256199
HUBZone Owned: N
Woman Owned: N
Socially and Economically Disadvantaged: N
Principal Investigator
 Terry Brennan
 Senior Scientist
 (714) 772-7668
 tbrennan@tosc.com
Business Contact
 Glenn Tyler
Title: President
Phone: (714) 772-7668
Email: glenn.a.tyler@tosc.com
Research Institution
N/A
Abstract
Knowledge of key parameters of optical turbulence is essential for prediction of optical performance in both imaging and transmitting applications. Optimal techniques for compensation of turbulence effects are only as good as the knowledge of the turbulence environment. The basic required parameters are r0, the Fried coherence length, and fG, the Greenwood frequency. These are specifications of the mean spatial and temporal statistics of the turbulence. Generally, these parameters plus the Kolmogorov spectrum are utilized for analysis and simulation of optical propagation through turbulence. It is recognized that the Hill spectrum, including inner scale, L0, is a more realistic model of index variations. This model includes a turbulence enhancement in a spectral subrange prior to the inner scale roll-off. Knowledge of this enhancement and the subsequent roll-off is important for predicting the statistics of both phase and scintillation effects and has a direct impact on adaptive optics design and performance. A technique, and sensor design, is proposed that is capable of estimating r0, fG, and L0 as well as scintillation statistics. The technique has been demonstrated in analysis and simulation. A prototype sensor will be built and the technique will be demonstrated in a range of turbulence environments.

* information listed above is at the time of submission.

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