V.V. Rodionov - D.Sc. (Eng.), Professor, Academician of Academy of Sciences of Applied Radio electronics;Professor of South Ural State University (National Research University);Head of Scientific and Technical Centre of JSC - Chelyabinsk radioplant "Polyot". E-mail: rodionov_vv74@mail.ru
S.L. Ratseburzhinsky - Expert of JSC - Chelyabinsk radioplant "Polyot". E-mail: rsl@rbcmail.ru

The article considers the problem of detecting radar responses aircraft, the transmission of information to the international system of secondary radar ATCRBS. Secondary radar system consists of a radar transponder located on board the aircraft, and secondary radar located in ground. In a secondary radar system performs the function of a receiver of the interrogator and the response signals. Signals requests and responses are different codes and carrier frequencies. The processing of the response pulses calculated coordinates of the aircraft, the height and number of sides. The main difficulty in finding arises when responses from two or more aircraft overlap. Using detectors based comparator or on the basis of an agreed share does not allow to catch each other answers. The authors propose to use as a detector detector optimal algorithm based on game-theoretic model of signal detection on the background noise [1]. The article describes the sequence of creation of such a receiver . The authors carried out a comparative analysis of SSR detection signals when using the matched filter and optimum detection algorithm. The analysis found that the use of the receiver based on the optimal detection algorithm can improve immunity and measurement range.