Decoder for secondary radar system - compares signals transmitted by aircraft with those of aircraft expected in supervised space

摘要

Binary coded signals transmitted by the aircraft are received by a central unit and stored and the expected signals are set by switches in one or several operational units. The central units is seprate from the operational units; it converts the received signal into a series pulse train and the mode of operation is stored in parallel in two separate stores, after which it transmits them to the operational units. The received pulse train is tested in each operational unit for correct transmission of test bits and a comparator is provided in each operational unit for each expected signal, to whose inputs the received and the signals stored in a matrix are applied; when the two pulse trains coincide, it delivers a pulse.