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:
- wavelength
Quantity
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.
- wavelength
- Returns:
- wave_deriv
Quantity
object (number or sequence) Derivative d(wave_vacuum) / d(wave_air).
- wave_deriv