PlaneR0

MATLAB

[r0, r0Screen] = PlaneR0(alpha,lambda,Geom,Atm)

Description

Computes the plane wave coherence diameter (Fried parameter) given turbulence assumptions, propagation geometry, and wavelength. Also calculates screen r0 if input Atm is a discrete structure from AtmStruct. 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 structure 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
r0 [vector]	Plane wave coherence diameter (m)
r0Screen [matrix]	Plane wave coherence diameter at each phase screen. r0Screen is empty if Atm is not a discrete structure.

References

Fried, D. L. "Limiting Resolution Looking Down through the Atmosphere." J. Opt. Soc. Am. 56, 1380-1384 (1966).

Examples

[r0, r0Screen] = PlaneR0(alpha,lambda,Atm)
[r0, r0Screen] = PlaneR0(alpha,lambda,Geom,Atm)
- Geom and Atm must have same values for hp, ht, and rd.
[r0, r0Screen] = PlaneR0(alpha,lambda,Geom,Cn2Model)
- Cn2Model as turbulence profile string. r0Screen will be empty.
r0 = PlaneR0(alpha,lambda,hp,ht,rd,Cn2Model)