colour.rayleigh_scattering

colour.rayleigh_scattering(wavelength: ArrayLike, CO2_concentration: ArrayLike = CONSTANT_STANDARD_CO2_CONCENTRATION, temperature: ArrayLike = CONSTANT_STANDARD_AIR_TEMPERATURE, pressure: ArrayLike = CONSTANT_AVERAGE_PRESSURE_MEAN_SEA_LEVEL, latitude: ArrayLike = CONSTANT_DEFAULT_LATITUDE, altitude: ArrayLike = CONSTANT_DEFAULT_ALTITUDE, avogadro_constant: ArrayLike = CONSTANT_AVOGADRO, n_s_function: Callable = air_refraction_index_Bodhaine1999, F_air_function: Callable = F_air_Bodhaine1999) → NDArrayFloat

Return the Rayleigh optical depth \(T_r(\lambda)\) as function of wavelength \(\lambda\) in centimeters (cm).

Parameters:

• wavelength (ArrayLike) – Wavelength \(\lambda\) in centimeters (cm).

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

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

• pressure (ArrayLike) – Surface pressure \(P\) of the measurement site.

• latitude (ArrayLike) – Latitude of the site in degrees.

• altitude (ArrayLike) – Altitude of the site in meters.

• avogadro_constant (ArrayLike) – 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:

Rayleigh optical depth \(T_r(\lambda)\).

Return type:

numpy.ndarray

Warning

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

References

[BWDS99], [Wikipedia01d]

Examples

>>> rayleigh_optical_depth(555 * 10e-8)  
0.0936290...