SphericalTheta0

MATLAB

Theta0 = SphericalTheta0(alpha,lambda,Geom,Atm)

Description

Computes the spherical wave isoplanatic angle given turbulence assumptions, propagation geometry, 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)
Geom [struct/list]	Geometry parameters. Can be a structure from GeomStruct or a comma separated list of (...,hp,ht,rd) - not required if Atm is a struct from AtmStruct
hp [scalar]	Altitude of transmit/receive platform (m)
ht [scalar]	Altitude of target (m)
rd [scalar]	Downrange of target along spherical earth surface (m)
Atm [struct/string]	Atmospheric modeling parameters. Can be a structure from AtmStruct or a turbulence profile model to be used.

Return Values

Return Values	Description
Theta0 [vector]	Spherical wave isoplanatic angle (rad)

References

Fried, D. L. "Anisoplanatism in Adaptive Optics." J. Opt. Soc. Am. 72, 52-61 (1982).

Examples

>> theta0 = SphericalTheta0(1.0,1.0e-6,AtmStruct)

Compute theta0 at 1 micron using the turbulence model in the input Atm struct.

>> theta0 = SphericalTheta0(2.0,1.0e-6,GeomStruct,AtmStruct)

Compute theta0 scaling the input turbulence model by a factor of 2 in addition to any turbulence multiplier already in the Atm struct. If Geom and geometry in Atm are not consistent, Atm will be updated.

>> theta0 = SphericalTheta0(2.0,1.0e-6,GeomStruct, ...

{'HufnagelValley',15,1e-15})

Compute theta0 scaling the input turbulence model by a factor of two. To pass additional parameters to the model, pass the model name and parameters in a cell array.

>> theta0 = SphericalTheta0(1.0,1.0e-6,10,3000,10000,'HV57')

Compute theta0 passing geometry as a list with a continuous turbulence model.