colour.phenomenons Package

Module Contents

colour.phenomenons.scattering_cross_section(wavelength, CO2_concentration=300, temperature=288.15, avogadro_constant=6.02214179e+23, n_s=<function air_refraction_index_Bodhaine1999 at 0x2b436dc47140>, F_air=<function F_air_Bodhaine1999 at 0x2b436dc47410>)

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) – Wavelength \(\lambda\) in centimeters (cm).
  • CO2_concentration (numeric, optional) – \(CO_2\) concentration in parts per million (ppm).
  • temperature (numeric, optional) – Air temperature \(T[K]\) in kelvin degrees.
  • avogadro_constant (numeric, 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

Warning

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

Examples

>>> scattering_cross_section(555 * 10e-8)  
4.6613309...e-27
colour.phenomenons.rayleigh_optical_depth(wavelength, CO2_concentration=300, temperature=288.15, pressure=101325, latitude=0, altitude=0, avogadro_constant=6.02214179e+23, n_s=<function air_refraction_index_Bodhaine1999 at 0x2b436dc47140>, F_air=<function F_air_Bodhaine1999 at 0x2b436dc47410>)

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

Parameters:
  • wavelength (numeric) – Wavelength \(\lambda\) in centimeters (cm).
  • CO2_concentration (numeric, optional) – \(CO_2\) concentration in parts per million (ppm).
  • temperature (numeric, optional) – Air temperature \(T[K]\) in kelvin degrees.
  • pressure (numeric) – Surface pressure \(P\) of the measurement site.
  • latitude (numeric, optional) – Latitude of the site in degrees.
  • altitude (numeric, optional) – Altitude of the site in meters.
  • avogadro_constant (numeric, 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:

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

Return type:

numeric

Warning

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

Examples

>>> rayleigh_optical_depth(555 * 10e-8)  
0.1004070...
colour.phenomenons.rayleigh_scattering(wavelength, CO2_concentration=300, temperature=288.15, pressure=101325, latitude=0, altitude=0, avogadro_constant=6.02214179e+23, n_s=<function air_refraction_index_Bodhaine1999 at 0x2b436dc47140>, F_air=<function F_air_Bodhaine1999 at 0x2b436dc47410>)

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

Parameters:
  • wavelength (numeric) – Wavelength \(\lambda\) in centimeters (cm).
  • CO2_concentration (numeric, optional) – \(CO_2\) concentration in parts per million (ppm).
  • temperature (numeric, optional) – Air temperature \(T[K]\) in kelvin degrees.
  • pressure (numeric) – Surface pressure \(P\) of the measurement site.
  • latitude (numeric, optional) – Latitude of the site in degrees.
  • altitude (numeric, optional) – Altitude of the site in meters.
  • avogadro_constant (numeric, 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:

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

Return type:

numeric

Warning

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

Examples

>>> rayleigh_optical_depth(555 * 10e-8)  
0.1004070...
colour.phenomenons.rayleigh_scattering_spd(shape=SpectralShape(360, 830, 1), CO2_concentration=300, temperature=288.15, pressure=101325, latitude=0, altitude=0, avogadro_constant=6.02214179e+23, n_s=<function air_refraction_index_Bodhaine1999 at 0x2b436dc47140>, F_air=<function F_air_Bodhaine1999 at 0x2b436dc47410>)

Returns the rayleigh spectral power distribution for given spectral shape.

Parameters:
  • shape (SpectralShape, optional) – Spectral shape used to create the rayleigh scattering spectral power distribution.
  • CO2_concentration (numeric, optional) – \(CO_2\) concentration in parts per million (ppm).
  • temperature (numeric, optional) – Air temperature \(T[K]\) in kelvin degrees.
  • pressure (numeric) – Surface pressure \(P\) of the measurement site.
  • latitude (numeric, optional) – Latitude of the site in degrees.
  • altitude (numeric, optional) – Altitude of the site in meters.
  • avogadro_constant (numeric, 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:

Rayleigh optical depth spectral power distribution.

Return type:

SpectralPowerDistribution

Examples

>>> rayleigh_scattering_spd()  
<colour.colorimetry.spectrum.SpectralPowerDistribution object at 0x...>