Precision design, analysis and manufacturing of quasi-optic lens/reflector antenna systems for CubeSat MMW/SMMW radiometers

The prediction of weather and climate from meso to global scales necessitates the use of precision satellite data, closely sampled in both temporal and spatial extent. Atmospheric temperature variations of 0.1 K or smaller over a decade are relevant to the detection and prediction of global change. Radiometric sounding measurements used to provide such data are strongly affected by the main-beam, ohmic, and spillover efficiencies of the optics, as well as inhomogeneities in the scene and background radiation fields. The interpretation of radiometric data is also affected by the accuracy with which these efficiencies can be determined. To emphasize this point, it is to be noted that a space-borne radiometer observing a 300 K scene in cold space requires that the error in the estimation of spillover efficiency be 0.03% or smaller in order to obtain corrected brightness temperature measurement accuracies of ∼0.1 K or better.