The purpose of this chapter is to use analytical expressions for the comparison of thermal microwave radiation as functions of temperature, layer thickness, absorption and scattering coefficient. For an observer from above, a growing cover is an increased screening of the underlying surface by scattering, absorption and emission. Here the discussion is limited to soft covers by which is meant that the transition from the atmosphere to the canopy is gentle enough to avoid reflections. Reflection is accounted for at the bottom surface, and volume interactions are allowed inside the cover. For simplicity polarisation effects have been neglected, and the angular dependence has been treated in a simplified way. The models can be extended to include better angular dependence, polarisation, hard covers and multi-layer systems.

Inspec keywords: land surface temperature; remote sensing; atmospheric spectra; vegetation; radiative transfer

Other keywords: temperature function; thermal microwave radiation; volume interaction analysis; hard cover system; scattering coefficient; multilayer system; radiative-transfer model; absorption coefficient; remote sensing; surface emission; polarisation effect

Subjects: Other topics in solid Earth physics