CiddorPy: Python functions for phase and group refractive index in air

CiddorPy.py: Python module which provides functions providing the group and phase index of refraction in air depending on wavelength, temperature, pressure, relative humidity and carbon dioxide contents. They are based on the works by Ciddor [Appl. Opt. 35, 1566 (1996)] and Ciddor and Hill [Appl. Opt. 38, 1663 (1999)]. The latter has been corrected for a sign error. Estimates of the expanded measurement uncertainties of this formulae are given using the approximations by Stone and Zimmerman [https://emtoolbox.nist.gov/Wavelength/Documentation.asp]. CiddorPyDemonstrator.py: This program provides a simple text-based calculation interface demonstrating the capabilities of the CiddorPy functions. contact: florian.pollinger@ptb.de The author assumes no liability for any application of this code. The software was developed in the course of the 18SIB01 Geometre project. This project has received funding from the EMPIR programme co-financed by the Participating States and from the European Union’s Horizon 2020 research and innovation programme.