This paper deals with the problem of optimum detection of radar signals by means of a multistatic configuration of sensors. Starting from the case of multiple observations, a systematic analysis of the model leads to a unified optimum receiver for signals fluctuating according to Swerling I, II, III & IV models. In these instances the receiver performances are evaluated by adopting an original method. Finally, possible suboptimum solutions are found, through which considerable streamlining of processing structures can be achieved.