GrismThetaGrismTheta - Angle between normal to detector plane and reference ray

Description:
This attribute gives the angle of incidence of light of the reference wavelength (given by attribute GrismWaveRGrismWaveR) onto the detector. Specifically, it holds the angle (in radians) between the normal to the detector plane and an incident ray at the reference wavelength. The default value is 0.0.
Type:
Double precision.
Class Applicability:
GrismMapGrismMap
All GrismMaps have this attribute.