Visualizing aero-optic interactions about a nose-mounted turret

James M. Cicchiello; Scott Harris; Curt A. Prudden; James Neiswender; David W. Bope; Curtis J. Harkrider; Thomas G. Moore; Brian Stadler; Larry Stotts

doi:10.1117/12.850895

4 May 2010 Visualizing aero-optic interactions about a nose-mounted turret

James M. Cicchiello, Scott Harris, Curt A. Prudden, James Neiswender, David W. Bope, Curtis J. Harkrider, Thomas G. Moore, Brian Stadler, Larry Stotts

Author Affiliations +

Proceedings Volume 7685, Atmospheric Propagation VII; 76850C (2010) https://doi.org/10.1117/12.850895
Event: SPIE Defense, Security, and Sensing, 2010, Orlando, Florida, United States

Abstract

One aspect of the propagation-physics challenge associated with airborne, free-space, optical communications (FSOC), for example, is the characterization and mitigation of link losses due to aero-optic interactions. That is, air-density gradients due to compressibility effects in turbulent boundary layers, separated flows, and freeshear flows can disturb the wavefront in the near field of the transceiver. To better understand these aero-optical mechanisms, a model of a nose-mounted, FSOC transceiver recently was placed in a compressible-flow wind tunnel, and the resulting wavefront degradations, as a function of flow scenario, were recorded. High-speed, time-resolved movies of the aero-optic disturbances have been realized, using a Schlieren-imaging technique, and a very-highframe-rate camera. Discrete, vortical structures (amid otherwise-irregular shedding) were seen to emerge and convect past the clear aperture. The frequencies of these disturbances have been estimated from the movies, and these have been compared with high-speed, time-resolved wavefront reconstructions. Losses of -3.5 dB (for the case of Mach - 0.45 at 10 kft, side view, and λ - 1.55 μm, for example), and disturbance frequencies of - 1200 Hz (and higher) were observed. The system-level impact of the resulting wavefront degradations will be discussed.

Citation Download Citation

James M. Cicchiello, Scott Harris, Curt A. Prudden, James Neiswender, David W. Bope, Curtis J. Harkrider, Thomas G. Moore, Brian Stadler, and Larry Stotts "Visualizing aero-optic interactions about a nose-mounted turret", Proc. SPIE 7685, Atmospheric Propagation VII, 76850C (4 May 2010); https://doi.org/10.1117/12.850895

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available