Absorption data

Absorption datasets tabulate the volume absorption coefficient of a gas mixture against spectral index, mixture’s components’ volume fraction, air pressure and air temperature.

For monochromatic absorption datasets, the spectral index consists of a radiation wavelength or radiation wavenumber coordinate.

For CKD absorption datasets, the spectral index consists of two coordinates:

• the center of the spectral band (in wavelength or wavenumber space)

• the absorption coefficient cumulative probability, or \(g\)-point.

Data access

Distributed absorption datasets are available from the Eradiate store.

Note

You can also plug in your own datasets, provided they comply with the below specifications.

Specifications

Monochromatic

Monochromatic absorption coefficient datasets include one data variable:

• volume absorption coefficient (sigma_a),

and at least four dimension coordinates:

• radiation wavelength or radiation wavenumber (w),

• gas mixture mole fractions (x_M where M is the molecule formula, e.g. x_H2O),

• air pressure (p),

• and air temperature (t).

CKD

CKD absorption coefficient datasets include at least two data variables:

• sigma_a [x_M, p, t, w, g] : volume absorption coefficient

• wbounds [wbv, w] : band spectral bounds

one optional data variable:

• error [w, ng] : relative error on atmosphere band-averaged transmittance,

at least five dimension coordinates:

• w : radiation wavelength or radiation wavenumber of the band center,

• wbv : band wavelength bounds,

• g : quadrature \(g\)-point,

• x_M (where M is the molecule formula, e.g. x_H2O, x_CO2): gas mixture mole fractions (1 to \(N_M\) coordinates where \(N_M\) is the number of molecules in the mixture),

• p : air pressure,

• t : and air temperature,

and, if the data variable error is present:

• ng : number of quadrature \(g\)-point.

Available datasets

Monochromatic datasets

Available monochromatic datasets

Codename	Spectral range	Sampling resolution	Online data store path
gecko	[250, 3125] nm	0.01 \(\rm{cm}^{-1}\) in [250, 300] \(\cup\) [600, 3125] nm, 0.1 \(\rm{cm}^{-1}\) in [300, 600] nm	spectra/absorption/mono/gecko/
komodo	[250, 3125] nm	1 \(\rm{cm}^{-1}\)	spectra/absorption/mono/komodo/

CKD datasets

Available CKD datasets

Codename	Spectral range	Band widths	Online data store path
monotropa	[250, 3125] nm	100 \(\rm{cm}^{-1}\)	spectra/absorption/ckd/monotropa/
panellus	[250, 3125] nm	1 nm	spectra/absorption/ckd/panellus/
mycena	[250, 3120] nm	10 nm	spectra/absorption/ckd/mycena/