pybsm.radiance.functional.giqe_radiance

pybsm.radiance.functional.giqe_radiance(*, atm: ndarray, is_emissive: int) → tuple[ndarray, ndarray]

This function provides target and background spectral radiance as defined by the GIQE.

Parameters:

• atm –

  an array containing the following data: atm[:,0] - wavelengths from .3 to 14 x 10^-6 m in 0.01x10^-6 m steps

  atm[:,1] - (TRANS) total transmission through the defined path

  atm[:,2] - (PTH THRML) radiance component due to atmospheric emission and scattering received at the observer

  atm[:,3] - (SURF EMIS) component of radiance due to surface emission received at the observer

  atm[:,4] - (SOL SCAT) component of scattered solar radiance received at the observer

  atm[:,5] - (GRND RFLT) is the total solar flux impingement on the ground and reflected directly to the sensor from the ground. (direct radiance + diffuse radiance) * surface reflectance

  NOTE: Units for columns 1 through 5 are in radiance W/(sr m^2 m).

• is_emissive – is_emissive = 1 for thermal emissive band NIIRS, otherwise is_emissive = 0

Returns:

target_radiance:

apparent target spectral radiance at the aperture including all atmospheric contributions

background_radiance:

apparent background spectral radiance at the aperture including all atmospheric contributions

NOTE:

The nighttime emissive case is well approximated by subtracting off atm[:,4] from the returned values.