Qualifying IMG tropical spectra for clear sky

The problem of cloud detection for the Interferometric Monitoring of Greenhouse Gases spectrometer has been addressed by considering a set of thresholding tests which takes full advantage of the high spectral resolution of the sensor. The methodology has been applied to a case study consisting of spectra recorded in the tropics on sea surface, although the scheme may be easily extended to other latitudes. The algorithm is very efficient because it uses only the observed spectrum and no on-line radiative transfer calculation is needed. Based on this cloud detection scheme a set of clear-sky tropical spectra have been identified to be used by the scientific community for further studies such as retrieval of atmospheric properties and high spectral resolution radiative transfer modeling. (C) 2002 Elsevier Science Ltd. All rights reserved.