Near-UV Atmospheric Background Characterization for an Earth-watching Space-based Observatory

The observation of Ultra-High Energy Cosmic Radiation (UHECR) from Space might take benefit from some preliminary ancillary measurements. One of the most important is the characterization of the near-UV background, produced in the atmosphere by natural and man-made phenomena, that affects the performances of any UHECR Space-detector. An accurate measurement of these effects is very helpful to design and optimize the instrument, in particular as it affects its duty cycle and signal-to-noise ratio. Here we present some preliminary considerations about the design of a micro-satellite mission devoted to the characterization of this kind of background. We focus in particular on the basic requirements of the measurement apparatus.