Both instruments are based on a circular scanning sky strategy, consisting of a 60 rpm spinning flat mirror directing the sky radiation into an off-axis paraboloidal antenna, whose size is 1.8-m in the COSMO15 and 2.4-m in the COSMO11.
12.
The ideal response, in such a situation, is simply to accommodate and work around the excessive demands " find " a source that says " the sky is blue ", in those exact words if necessary, or settle for a wording that you " can " source to the hilt ( " diffuse sky radiation consists mainly of the shorter wavelengths of light " ).
13.
See our article on Rayleigh scattering for an explanation of why the sky usually appears blue, but why thicker slabs of air ( as seen at sunset, for example ) can appear other colours . ( See also green flash for a really neat atmospheric phenomenon . ) Lastly, check out Mie theory for an examination of how suspended particulate matter ( volcanic dust, industrial pollution ) can " also " colour the sky . ( Oops & mdash; I shouldn't forget diffuse sky radiation, too . ) The apparent blue colour of the sky isn't due solely to intrinsic'colour'of the air, but a combination of scattering effects, the nature of the source of illumination ( the Sun ), and the sensitivity of the photoreceptors in our eyes . talk ) 03 : 51, 1 November 2005 ( UTC)
