There is disclosed apparatus for, and a method of identifying radar signals from selected of their parameters, such as azimuth, instantaneous frequency, pulse duration and the like, so that countermeasures may be initiated. Since the signals are sensed from several radars and occur at short intervals of the order of one microsecond or less, and, for effective countermeasures, the radar systems must be identified in a very short time, instantaneous evaluation of the parameters is demanded. The signals are evaluated by a matrix including a pattern of adaptive memory elements, such as magnetic or solid state memory elements (minstors) disposed in columns and rows. A parameter is assigned to the adaptive elements in each column so that each row of adaptive elements corresponds to a set of parameters. The elements in each row are encoded with a different set of adaptations corresponding to the parameters which it is anticipated will match the parameters of the radar systems. Adaptations derived from sensed parameters of a radar system, each corresponding to the parameters assigned to each column, are simultaneously impressed respectively on each column in comparing relationship with the encoded adaptation of the elements. The comparison takes place in real time (instantaneously) for all parameters. A measure of the total deviation of the impressed adaptation from the encoded adaptation for the elements of the row is derived for each row and a determination is made as to the identity of a radar system from the row manifesting the minimum deviation.