When choosing the wavelengths for a multispectral radiometer, it is important to consider the information content of the proposed measurement set. Eigenanalysis provides valuable information about the number of independent pieces of information which can be obtained from a proposed set of measurement wavelengths. This method has been used to determine a suitable measurement wavelength set for an instrument: we recommend seven channels between 0.368 and 2.23 μm. The interdependence of measurements means that one measurement may often be predicted from the others to within the experimental accuracy. Eigenanalysis provides a means of making such predictions and has been applied in this paper to predict the aerosol optical thickness at 0.61 μm from optical thickness measurements at other wavelengths. This would allow the ozone contribution to optical thickness to be extracted from this measurement. ¿ American Geophysical Union 1996