PropagationController is a special purpose system class used for setting various propagation modeling options. These options include the mesh parameters, the type of reference wavefront (planar or spherical), spatial filtering and absorbing boundaries, and the types of models to use for point sources and speckle imaging.
The AtmoPath library system contains PropagationControllers, so it is frequently unnecessary to explicitly insert Propagation Controllers into a WaveTrain system. See the WT User Guide for further discussion of the conditions that warrant explicit use f the PropagationController.
A PropagationController can be connected anywhere along the path between an optical source and an optical sensor, and it is required that there be one somewhere on the path, if there is an optical propagation on it. If there are two or more PropagationControllers along the same source-sensor path, the one nearest the source overrides the others. Thus placing a PropagationController on a common path for two or more sources means that it will control the propagation options for all the sensors, unless another PropagationController, typically placed on some non-common part of the path, is used to override it.
The atmospheric dispersion option ("useDispersion" ="true") in PropagationController can still be used, but a separate DispersionController is now available that has greater functionality. (Dispersion allows the treatment of the slightly different paths taken through phase screens by different wavelengths.) The bending of ray paths is calculated relative to a straight path taken by light with the "nominalWavelength".

Parameters
targetGrid	GridGeometry	Geometry of propagation grid at sensor aperture	grid_with_origin_on_mesh(nxy,dxy)
xReferenceFocus	float	Focus to put in the reference wave (0 or 1e20 unless using SWP)	0.0
yReferenceFocus	float	Focus to put in the reference wave (0 or 1e20 unless using SWP)	0.0
oneTimeSpatialFilter	constFilter&	See filter documentation; used to remove high spatial frequency content from initial wavefront	NullFilter()
spatialFilter	constFilter&	See filter documentation; used to remove high spatial frequency content at each propagation step	NullFilter()
absorbingBoundary	constFilter&	See filter documentation; used to remove energy near the edge of the propagation mesh	NullFilter()
pointSourceModel	PointSourceModel	See point source/speckle documentation; sets which point source model is used	DEFAULT_PSM
speckleModel	SpeckleModel	See point source/speckle documentation; sets which speckle model is used	DEFAULT_SM
superApDiameter	float	Defines a circular region at the aperture plane which in vacuum would be uniformly illuminated; used in modeling point sources and surface speckle	1.5 * Dap
edgeSigma	float	Defines a gaussian round off at the edge of the superaperture; used in modeling point sources and surface speckle	5.0 * dxy
useDispersion	bool	Flag, model atmospheric dispersion; don't set here - use DispersionController instead	false
nominalWavelength	float	Nominal wavelength (m) for dispersion calculations; don't set here - use DispersionController instead	0.0
Inputs
incident	WaveTrain	Describes all light incident	WaveTrain()
Outputs
transmitted	WaveTrain	Describes all light transmitted
Subsystems
Last Saved: Fri Feb 01 13:52:57 MST 2008 by TVE version 2007B