Abstract: A method of and system for mortar fuze apex arming is disclosed in which a icroprocessor circuit is added to the M734 class of mortar proximity fuzes such that, at launch, the microprocessor measures the turbine-alternator frequency and the Doppler frequency and uses those values to calculate or look up the charge and angle used by the gunner firing the mortar as well as the time of flight to the trajectory apex, based on stored firing table or equation information. The microprocessor then causes the electrical arming of the fuze at the apex of the flight of the mortar round, using existing arming circuits already present in the M734 class of mortar proximity fuzes. Alternatively, the microprocessor may cause the electrical arming of the fuze just prior to the desired height of burst for the mortar round.