ScreenR0

MATLAB

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

Description

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.

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. 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.*Atm.dz. If intFlag=true, calculation will integrate Atm.Cn2Eval over the phase screen segments

Return Values

Return Values	Description
r0s [vector]	Coherence diameter for each phase screen (m)

Examples

>> 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