colour.scattering_cross_section#

colour.scattering_cross_section(wavelength: FloatingOrArrayLike, CO2_concentration: FloatingOrArrayLike = CONSTANT_STANDARD_CO2_CONCENTRATION, temperature: FloatingOrArrayLike = CONSTANT_STANDARD_AIR_TEMPERATURE, avogadro_constant: FloatingOrArrayLike = CONSTANT_AVOGADRO, n_s_function: Callable = air_refraction_index_Bodhaine1999, F_air_function: Callable = F_air_Bodhaine1999) FloatingOrNDArray[source]#

Return 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 (FloatingOrArrayLike) – Wavelength \(\lambda\) in centimeters (cm).

  • CO2_concentration (FloatingOrArrayLike) – \(CO_2\) concentration in parts per million (ppm).

  • temperature (FloatingOrArrayLike) – Air temperature \(T[K]\) in kelvin degrees.

  • avogadro_constant (FloatingOrArrayLike) – Avogadro’s number (molecules \(mol^{-1}\)).

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

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

Returns

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

Return type

numpy.floating or numpy.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