Low-order polynomial

Fig 3.3.1.7.1: Low-order polynomial representing broadband phenomena such as the effects of scattering.

Image: AT2-ELS

In contrast to the spectra arising from molecular absorption, the extinction caused by scattering — whether Rayleigh (molecular) or Mie (aerosol) scattering — or other non-molecular absorption process changes much less rapidly with wavelength.

Because of this relatively slow change with wavelength these effects are sometimes called broadband effects.

Within the wavelength range in which we are interested these effects can be represented by a low-order polynomial.