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GrismNRP - The rate of change of refractive index with wavelength

Description:
This attribute holds the rate of change of the refractive index of the grism material with respect to wavelength at the reference wavelength (given by attribute GrismWaveR). The default value is 0.0 (the appropriate value for a pure grating disperser with no prism). The units of this attribute should be consistent with those of attributes GrismWaveR and GrismG.
Type:
Double precision.
Class Applicability:
GrismMap
All GrismMaps have this attribute.


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AST A Library for Handling World Coordinate Systems in Astronomy
Starlink User Note 211
R.F. Warren-Smith & D.S. Berry
24th May 2011
E-mail:ussc@star.rl.ac.uk

Copyright (C) 2009 Science \& Technology Facilities Council