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

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.

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 
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. 

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


>> [r0, r0Screen] = PlaneR0(1.0,1.0e-6,AtmStruct); 

  • Compute r0 at 1 micron using the turbulence model in the input Atm struct.
>> [r0, r0Screen] = PlaneR0(2.0,1.0e-6,GeomStruct,AtmStruct) 

  • Compute r0 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.
>> [r0, r0Screen] = PlaneR0(1.0,1.0e-6,GeomStruct,'HV57') 

  • Cn2Model as turbulence profile string. r0Screen will be empty.
>> r0 = PlaneR0(1.0,1.0e-6,10,3000,10000,{'HufnagelValley',15,1e-15}) 

  • Continous Atm model with geometry as a list. To pass additional parameters to the model, pass the model name and parameters in a cell array.

See Also
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