Ring Effect

These classes are used to calculate the ‘Ring spectrum’ which is used to account for inelastic atmospheric scattering in DOAS retrievals.

Rotational Raman Cross Sections

class skdoas.ring.rotational_raman_lines.RotationalRamanLines
class skdoas.ring.rotational_raman_lines.RotationalRamanLinesN2

Calculates N2 rotation Raman lines according to Chance and Spurr (1997) using the data supplied with Chance and Martin (2017) on the Oxford University Press website (http://global.oup.com/booksites/content/9780199662104/data/).

References

K. V. Chance and R. J. D. Spurr. Ring effect studies: Rayleigh scattering, including molecular parameters for rotational Raman scattering, and the Fraunhofer spectrum. Applied Optics, 36(21):5224-5230, 1997.

Kelly Chance and Randall V. Martin. Spectroscopy & Radiative Transfer of Planetary Atmospheres. Oxford University Press, Oxford, United Kingdom, 2017.

class skdoas.ring.rotational_raman_lines.RotationalRamanLinesO2

Calculates O2 rotation Raman lines according to Chance and Spurr (1997) using the data supplied with Chance and Martin (2017) on the Oxford University Press website (http://global.oup.com/booksites/content/9780199662104/data/).

References

K. V. Chance and R. J. D. Spurr. Ring effect studies: Rayleigh scattering, including molecular parameters for rotational Raman scattering, and the Fraunhofer spectrum. Applied Optics, 36(21):5224-5230, 1997.

Kelly Chance and Randall V. Martin. Spectroscopy & Radiative Transfer of Planetary Atmospheres. Oxford University Press, Oxford, United Kingdom, 2017.

Ring Spectrum

class skdoas.ring.ring_spectrum.RingSpectrum(solar_spectrum_wavelength: ~numpy.ndarray, solar_spectrum_irradiance: ~numpy.ndarray, n2_cross_sections: ~skdoas.ring.rotational_raman_lines.RotationalRamanLines = <skdoas.ring.rotational_raman_lines.RotationalRamanLinesN2 object>, o2_cross_sections: ~skdoas.ring.rotational_raman_lines.RotationalRamanLines = <skdoas.ring.rotational_raman_lines.RotationalRamanLinesO2 object>, interp_method: str = 'linear')

Calculates the ring spectrum from rotational Raman scattering of O2 and N2 particles. For use in DOAS retrievals.

Parameters:

  • solar_spectrum_wavelength (np.ndarray) – Array of wavelengths corresponding to the irradiance data.

  • solar_spectrum_irradiance (np.ndarray) – Solar top-of-atmosphere irradiance data.

  • n2_cross_sections (skdoas.ring.rotational_raman_lines.RotationalRamanLines) – Object that computes N2 rotational Raman cross sections.

  • o2_cross_sections (skdoas.ring.rotational_raman_lines.RotationalRamanLines) – Object that computes O2 rotational Raman cross sections.

  • interp_method (str) – Interpolation method for interpolating the provided solar spectrum (which should be convolved) onto the high resolution grid used for the Raman lines. Passed to scipy.interpolate.interp1d