SphericalIrradianceCovariance

MATLAB

D = SphericalIrradianceCovariance(alpha, d, Atm, wvl)

Description

Computes the irradiance covariance for a spherical wave given turbulence multiplier alpha, point spacings d, atmospheric modeling data in Atm, and wavelength in wvl. In this calculation, the light propagates from the target to the platform, which is consistent with calculations of SphericalRytov and SphericalR0. Uses the weak turbulence assumption.

Parameters

Parameters	Description
alpha [scalar]	Turbulence strength multiplier.
d [vector]	Separation of the points in the aperture plane (m).
Atm [struct]	Atmospheric modeling structure from AtmStruct.
wvl [scalar]	Optical wavelength (m).

Return Values

Return Values	Description
B [vector]	Irradiance covariance value

References

L. C. Andrews and R. L. Phillips, Laser Beam Propagation through Random Media, 2nd ed. Bellingham, Wash.: SPIE Press, 2005.

Examples

>> alpha = 1;

>> wvl = 0.5e-6;

>> G = SimpleGeom(0, 2e4, 0);

>> Atm = AtmStruct(G, 100, 'Cn2', 'HV57');

>> d = linspace(0, 0.5, 30);

>> B = SphericalIrradianceCovariance(alpha, d, Atm, wvl);

Irradiance covariance value for turbulence multiplier of 1, wavelength 0f 500 nm, collimated Gaussian source with beam radius 5 cm at 20 km propagating straight down, pupil-plane separations d, and atmospheric model Atm.