Abstract: This invention concerns the field of passive sonar systems simultaneously processing several linear antennas. This invention includes a method to eliminate ghost sources for a passive sonar having at least two linear antennas A and B, the method including: An initial acquisition step during which the signal received is measured at different moments ti, and for each antenna, the Doppler frequency f of the signal received is determined, as well as the potential values of the azimuth ? of the source; A second step of determining the potential values of the source performed by use of the measured azimuth ? frequency f values; A third step of eliminating ambiguity and rejecting ghost sources during which it is determined, for which of the potential sources, the speed and frequency values will satisfy, for each moment ti, the measurement equations linking the frequency of the signal received to the frequency f0 emitted by the source, at the source speed and position.

Abstract: This invention concerns the field of passive sonar systems simultaneously processing several linear antennas. This invention includes a method to eliminate ghost sources for a passive sonar having at least two linear antennas A and B, the method including: An initial acquisition step during which the signal received is measured at different moments ti, and for each antenna, the Doppler frequency f of the signal received is determined, as well as the potential values of the azimuth ? of the source; A second step of determining the potential values of the source performed by use of the measured azimuth ? frequency f values; A third step of eliminating ambiguity and rejecting ghost sources during which it is determined, for which of the potential sources, the speed and frequency values will satisfy, for each moment ti, the measurement equations linking the frequency of the signal received to the frequency f0 emitted by the source, at the source speed and position.

Abstract: The present invention relates to the angular calibration of passive reception systems such as sonars or active ones such as certain radars whose angular performance is inadequate. The invention proposes a method making it possible to perform antenna calibration using the detection system associated with this antenna under real operating conditions. The method according to the invention consists in making an immersed noisemaker deployed along a substantially rectilinear uniform trajectory and a submarine equipped with an antenna to be calibrated along any trajectory whatsoever, but nonrectilinear. The method according to the invention consists also in implementing a trajectography algorithm making it possible to determine the noisemaker-antenna relative distance at known instants the, and to deduce therefrom the trajectory followed by the noisemaker as well as the bearing corresponding to the positions of the noisemaker at the measurement instants.

Abstract: The present invention relates to the angular calibration of passive reception systems such as sonars or active ones such as certain radars whose angular performance is inadequate. The invention proposes a method making it possible to perform antenna calibration using the detection system associated with this antenna under real operating conditions. The method according to the invention consists in making an immersed noisemaker deployed along a substantially rectilinear uniform trajectory and a submarine equipped with an antenna to be calibrated along any trajectory whatsoever, but nonrectilinear. The method according to the invention consists also in implementing a trajectography algorithm making it possible to determine the noisemaker-antenna relative distance at known instants ti, and to deduce therefrom the trajectory followed by the noisemaker as well as the bearing corresponding to the positions of the noisemaker at the measurement instants.