Abstract: A method to detect and/or locate a mobile craft in a reception system making use of transmitters of opportunity, whose signal comprises elements enabling the synchronization of the receiver, wherein certain discriminating sequences are detected of the payload signal. Each transmission present on the carrier frequencies examined by the receiver or receivers is separated by the space/time filtering of the signals in each carrier frequency. The transmitters Ei corresponding to the signals received are identified. The pulse response of the propagation channel for each transmitter Ei and for each detection made on this transmitter are determined by measuring the instant of arrival of the path reflected by the mobile craft is measured and then its delay relative to the instant of transmission from the transmitter. The position of the mobile craft is deduced at the intersection of the ellipsoids defined by the foci constituted by the transmitters Ei from which signals are received and the receiver or receivers Rj.

Abstract: A method to detect and/or locate a mobile craft in a reception system making use of transmitters of opportunity, whose signal comprises elements enabling the synchronization of the receiver, comprises at least the following steps: a) detecting certain “discriminating” sequences of the payload signal; b) separating each transmission present on the carrier frequencies examined by the receiver or receivers by the space/time filtering of the signals in each carrier frequency; c) identifying the transmitters Ei corresponding to the signals received; d) determining the pulse response of the propagation channel for each transmitter Ei and for each detection made on this transmitter;) measuring the instant of arrival of the path reflected by the mobile craft and then its delay relative to the instant of transmission from the transmitter; h) deducing the position of the mobile craft at the intersection of the ellipsoids defined by the foci constituted by the transmitters Ei from which signals are received and the rece