PropagationController

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 LightLike system. See the LightLike 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".