Richard Holmes, Boeing LTS, Venkata Rao Gudimetla, Air Force Research Laboratories, Jeremy Bos, Air Force Research Laboratories, Jacob Lucas, Boeing Laser Technical Services
Keywords: Atmospheric Characterization, Scintillation, Turbulence
Abstract:
An experiment called COMBAT collected data in 2010 along paths between Mauna Loa and Haleakala to investigate atmospheric effects in long horizontal paths. The data has proven difficult to interpret in terms of conventional analyses and wave-optics simulations. Recent modifications to the wave-optics simulations have shown better agreement with a subset of the COMBAT data that is available for comparison. These modifications include (a) alternative Cn2 profiles along the path from Mauna Loa to Haleakala, (b) non-Kolmogorov turbulence exponents, (c) anisotropy of turbulence, (d) turbulence inner and outer scale effects, (e) transmitter telescope jitter, (f) camera noise, (g) camera saturation, and (h) spatial averaging due to the finite extent of the pixels. The presence of transmitter telescope jitter helps provide additional agreement with the temporal data, contributing as much or more to full-aperture fades as turbulence. With the inclusion of these effects, the general trends were obtained, in which measured scintillation increased with wavelength, and the correct spatial and temporal structure were obtained as quantified by autocorrelations.
Date of Conference: September 15-18, 2015
Track: Adaptive Optics & Imaging