air_to_vac_deriv

specutils.utils.wcs_utils.air_to_vac_deriv(wavelength, method='Griesen2006')[source]

Calculates the derivative d(wave_vacuum) / d(wave_air) using different methods.

Parameters:
wavelengthQuantity object (number or sequence)

Air wavelengths with an astropy.unit.

methodstr, optional

Method used to convert wavelength derivative. Options are: ‘Griesen2006’ (default) - from Greisen et al. (2006, A&A 446, 747), eqn. 66.

Returns:
wave_derivQuantity object (number or sequence)

Derivative d(wave_vacuum) / d(wave_air).