GreenwoodFreq

MATLAB

fG = GreenwoodFreq(alpha,lambda,S,Atm)

Description

Computes the Greenwood frequency for propagation given turbulence assumptions, engagement parameters, and wavelength. Returns NaN if propagation path intersects earth surface.

Parameters

Parameters	Description
alpha [vector]	Multiplier on turbulence model
lambda [scalar]	Wavelength of laser (m)
S [struct]	Engagement parameters. Must be a structure from EngagementStruct or GeomStruct.
Atm [struct]	Atmospheric modeling parameter structure from AtmStruct. Atm must have wind profile/heading if calculation with wind is desired.

Return Values

Return Values	Description
fG [vector]	Greenwood frequency (Hz)

References

Greenwood, D. P. "Bandwidth Specification for Adaptive Optics Systems." J. Opt. Soc. Am., 67,390-393 (1979).

Examples

>> fG = GreenwoodFreq(2.0,1e-6,GeomStruct,AtmStruct)

Compute Greenwood frequency at 1 micron for 2 times Cn2 model specified in the input Atm struct