Extinction coefficient - Also called attenuation coefficient, especially in reference to radar frequencies.) is the fractional depletion of radiance per unit path length.  Extinction is caused by absorption and scattering. The extinction coefficient is the sum of the absorption coefficient and the scattering coefficient, and generally depends on wavelength and temperature.

Backscatter coefficient - A measure of the fraction of incident radiation that is scattered directly back toward the source.

Integrated backscatter - soon

Color ratio - soon

Angstrom exponent - is the name of the exponent in the formula that's usually used to describe the dependency of the aerosol optical thickness, or aerosol extinction coefficient on wavelength . The Angström exponent is inversely related to the average size of the particles in the aerosol: the smaller the particles, the larger the exponent. Thus, Angström exponent is a useful quantity to assess the particle size of atmospheric aerosols or clouds, and the wavelength dependence of the aerosol/cloud optical properties. For example, cloud droplet, usually with large sizes and thus very smaller Angström exponent (nearly zero), is spectrally neutral, which means, e.g., the optical depth does not change with wavelength. This exponent is now routinely estimated by analyzing radiation measurements acquired on Earth Observation platforms, such as AErosol RObotic NETwork, or AERONET.

Aerosol optical depth (AOD) - lidar and sun photometry - The optical depth due to extinction by the aerosol component of the atmosphere. Aerosol optical depths typically decrease with increasing wavelength and are much smaller for longwave radiation than for shortwave radiation. Values vary widely depending on atmospheric conditions, but are typically in the range 0.02–0.2 for visible radiation.

Particle depolarization ratio - soon