Clutter in the solar blind ultraviolet in urban areas

In this paper it is shown that for E-O systems operating in the solar blind ultraviolet (SBUV) band, one has to consider the clutter noise since in most cases it will be the dominant factor in the sensor performance. Such clutter in various rural populated areas were sampled using a SBUV photon counter whose data was analyzed in terms of statistical and temporal characteristics. It is shown that the clutter in the SBUV can reach very high levels of counts with relatively long duration and that the properties of the so-called clutter "sources" are very similar. The temporal autocorrelation function can be approximated by two exponential functions, the first one with a short time constant and the second one with a relatively long time constant. Periodic modulation was observed in some cases. Its source is not explained at the present time.