Multichannel Radiometric Determination of Sea Surface Temperature: Parameterization of the Atmospheric Correction

Abstract

Synthetic computations of atmospheric transmissions and radiant energies are presented in order to simulate remote soundings of the sea surface temperature in two pairs of channels: ?8.7 and 11.6 ?m, on the one hand, and 11 and 12 ?m, on the other. This study takes into account absorptions by the line spectra of the various absorbers and by the water vapor continuum, first separately and then simultaneously. In the latter case, the accuracy of the linear parametric retrieval scheme previously presented by Imbault et al. (1978) is shown to depend mostly on the choice of wavelengths for the two channels and two criteria for optimization are introduced. Applying this parametric scheme to the analysis of the experimental results obtained, with the help of an airborne scanning radiometer, over a relatively humid atmosphere within the midlatitudes has led us to conclude that the usual expression for the water vapor absorption coefficient seems to overestimate this phenomenon.