d0 = PlaneD0(alpha,lambda,Geom,Lb,Atm)
Computes the section size of a laser guide star beacon (d0) given turbulence assumptions, propagation geometry, and wavelength. Output is appropriate for computing residual phase variance for compensation from laser guide star beacon as $(D/d0)^{5/3}$. Assumes the target object is at a long range compared to the beacon and hence plane wave analysis is appropriate. However, integration of Cn2 is done over the propagation path to target specified by Geom. Returns NaN if propagation path intersects earth surface.
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) |
Lb [scalar] |
Slant range of beacon (m) |
Atm [struct/string] |
Atmospheric modeling parameters. Can be a structure from AtmStruct or a turbulence profile model to be used. |
Return Values |
Description |
d0 [vector] |
LGS section size for plane wave target (m) |
>> d0 = PlaneD0(1.0,1.0e-6,20e3,AtmStruct)
Copyright (c) 2009. All rights reserved.
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