colour.scattering_cross_section

colour.scattering_cross_section(wavelength, CO2_concentration=300, temperature=288.15, avogadro_constant=6.02214179e+23, n_s=<function air_refraction_index_Bodhaine1999>, F_air=<function F_air_Bodhaine1999>)[source]

Returns the scattering cross section per molecule \(\sigma\) of dry air as function of wavelength \(\lambda\) in centimeters (cm) using given \(CO_2\) concentration in parts per million (ppm) and temperature \(T[K]\) in kelvin degrees following Van de Hulst (1957) method.

Parameters
  • wavelength (numeric or array_like) – Wavelength \(\lambda\) in centimeters (cm).

  • CO2_concentration (numeric or array_like, optional) – \(CO_2\) concentration in parts per million (ppm).

  • temperature (numeric or array_like, optional) – Air temperature \(T[K]\) in kelvin degrees.

  • avogadro_constant (numeric or array_like, optional) – Avogadro’s number (molecules \(mol^{-1}\)).

  • n_s (object) – Air refraction index \(n_s\) computation method.

  • F_air (object) – \((6+3_p)/(6-7_p)\), the depolarisation term \(F(air)\) or King Factor computation method.

Returns

Scattering cross section per molecule \(\sigma\) of dry air.

Return type

numeric or ndarray

Warning

Unlike most objects of colour.phenomena.rayleigh module, colour.scattering_cross_section() expects wavelength \(\lambda\) to be expressed in centimeters (cm).

References

[BWDS99], [Wikipedia01d]

Examples

>>> scattering_cross_section(555 * 10e-8)  
4.6613309...e-27