hypergas.unit_spectrum module

Calculate unit spectrum for matched filter.

class hypergas.unit_spectrum.Unit_spec(radiance, wvl_sensor, wvl_min, wvl_max, species='ch4', rad_source='model')

Bases: object

Calculate the unit spectrum.

Initialize unit_spec class.

Parameters:

• radiance (DataArray) – 3D radiance dataarray (bands, y, x).

• wvl_sensor (DataArray) – 1D [‘bands’] or 2D[‘bands’,’x’]. The central wavelengths (nm) of sensor.

• wvl_min (float) – The lower limit of wavelength (nm) for matched filter.

• wvl_max (float) – The upper limit of wavelength (nm) for matched filter.

• species (str) – The species to be retrieved: ‘ch4’ or ‘co2’. Default: ‘ch4’.

• rad_source (str) – The data (‘model’ or ‘lut’) used for calculating rads or transmissions. Default: ‘model’.

References

• rad_source (model): Gloudemans et al. (2008).

• rad_source (lut): only supporting ch4 and co2; Foote et al. (2021).

convolve_rads()

Calculate the convolved sensor-reaching rads or transmissions.

Returns:

convolved rads (DataArray) – 2D (conc*wvl) or 3D (bands*conc*wvl) radiances or transmissions for conc defined in the config.yaml file.

convolve_rads_lut()

Calculate the convolved sensor-reaching rads.

Returns:

convolved rads (DataArray) – 2D (conc*wvl) radiances for conc defined in the config.yaml file.

fit_slope(scaling=None)

Fit the slope for conc and rads.

Parameters:

scaling (float) – The scaling factor to ensure numerical stability. Default: None.