Aircraft to Ground Profiling: Turbulence Measurements and Optical System Performance Modeling

Authors

• Yakov Diskin, MZA Associates Corporation
• Matthew R. Whiteley, MZA Associates Corporation
• Mitchell Grose, MZA Associates Corporation
• Kevin Jackovitz, MZA Associates Corporation
• Richard Drye, MZA Associates Corporation
• Brandon Hampshire, MZA Associates Corporation
• Monte Owens, MZA Associates Corporation
• Eric Smith, MZA Associates Corporation
• Eric Magee, MZA Associates Corporation
• Matthew Kalensky, University of Notre Dame
• Eric Jumper, University of Notre Dame
• Stanislav Gordeyev, University of Notre Dame
• Aaron J. Archibald, Air Force Institute of Technology

Document Type

Article

Publication Date

11-2021

Abstract

A series of flight experiments have demonstrated a novel approach to measuring path-resolved optical turbulence quantities, such as 𝐶²_𝑛 , along an air-to-ground slant path. This paper describes the data acquisition experiments that involved two laser beams propagating between an orbiting airborne platform and a stationary ground terminal over an 8 km slant path. Ground-based and in-flight measurements were collected simultaneously, and 𝐶²_𝑛 profiles were computed using the difference of differential-tilt variance (DDTV) technique. This paper describes the DDTV technique that enables the path-resolved measurement of turbulence strength resulting in 𝐶²_𝑛 profiles. The resulting turbulence profiles reveal what is believed to be the aero-optical contamination from the aircraft boundary layer within the statistics closest to the aircraft. Therefore, the contamination of the aero-optical environment can be quantified with respect to the rest of the atmospheric propagation path. Lastly, this paper presents analyses that compare the measured atmospheric turbulence profiles to state-of-the-art atmospheric models. The analyses extend beyond 𝐶²_𝑛 comparisons and show the measurement-versus-modeling comparison in terms of key directed energy system propagation parameters such as Greenwood frequency, coherence diameter, Rytov number, isoplanatic angle, Tyler frequency, open-loop jitter, and open-loop Strehl ratio. The slant path turbulence is analyzed in the context of air-to-ground and ground-to-air directed energy systems.

Comments

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Funding note: Sponsored by Joint Transition Office and the Office of Naval Research, grant number ONR N00014-18-1-2112.

DOI

10.2514/1.J060580

Source Publication

AIAA Journal (ISSN 0001-1452)

Recommended Citation

Diskin, Y., Whiteley, M., Grose, M., Jackovitz, K., Drye, R., Hampshire, B., Owens, M., Smith, E., Magee, E., Kalensky, M., Jumper, E., Gordeyev, S., & Archibald, A. (2021). Aircraft to Ground Profiling: Turbulence Measurements and Optical System Performance Modeling. AIAA Journal, 59(11), 4610–4625. https://doi.org/10.2514/1.J060580