The performance of surface survillence radars is complicated by temporal changes of propagation loss, sea and rain clutter and target behaviour. This paper presents short and medium-term statistics using a real time pulse-to-pulse digital analyser operated in conjunction with high dynamic range logarithmic receivers fed from an experimental dual antenna coastal radar.Previous performance predictions18made for equipments operating in true diversity, themselves supported by extensive trials24over half minute intervals of observation, are now augmented with true pulse-by-pulse measurements on targets obtained in each common beam dwell time of a true composite dual channel experimental radar.Short-term measurements on sea and rain clutter show that predictions based on average or mean values of sea and rain clutter are a poor guide to true short term variations, but become more accurate over longer periods as found by others.25Illustrations from p.p.i.s are given of both targets and clutter from the experimental radar, showing the effects of optimum and non-optimum video processing of the output from the two channels and results from a captive target balloon at selected elevations are included.