r0s = ScreenR0(alpha,lambda,Geom,Atm,[Nscreens],[intFlag])

Computes the coherence diameter (Fried parameter) for each phase screen given turbulence assumptions, propagation geometry, and wavelength. 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. May be a structure from AtmStruct or turbulence profile to be used. 
Nscreens [scalar] 
(Optional) Number of phase screens. Required if Atm is a turbulence profile string or Atm is not a discrete structure 
intFlag [logical] 
(Optional) Flag indicating the integral type. If intFlag=false (default) calculation will use Atm.Cn2.* If intFlag=true, calculation will integrate Atm.Cn2Eval over the phase screen segments 
Return Values
Return Values 
r0s [vector] 
Coherence diameter for each phase screen (m) 

>> r0s = ScreenR0(1.0,1.0e-6,AtmStruct) 

  • Compute screen r0s at 1 micron using the turbulence model and screens in the input Atm struct.
>> r0s = ScreenR0(2.0,1.0e-6,GeomStruct,AtmStruct) 

  • Compute screen r0s 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.
>> r0s = ScreenR0(1.0,1.0e-6,GeomStruct,'HufnagelValley(h,15,1e-15)',10) 

  • Cn2Model as turbulence profile string and number of equally-spaced screens to compute
>> r0s = ScreenR0(1.0,1.0e-6,10,3000,5000,'HV57',10) 

  • Continous Atm model with geometry as a list

See Also
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