Abstract: The present invention is directed to a method of allowing a computational load caused by the implementation of conventional signal processing methods operating by multicopy correlation, by simultaneous correlation of the spectrum of the received signal to copies of the signal, each of the copies having a different Doppler shift. The multicopy correlation operation is a time-frequency transformation of the received signal. Synthetic spectra are found by selection of spectral lines and concatenation, starting from the spectrum of the received signal. An inter-spectral product is computed, in other words by the product of each synthetic spectrum with the concatenated conjugate spectrum of the corresponding Doppler copy. A frequency-time transformation of the inter-spectral products is performed.

Abstract: The present invention is directed to a method of allowing a computational load caused by the implementation of conventional signal processing methods operating by multicopy correlation, by simultaneous correlation of the spectrum of the received signal to copies of the signal, each of the copies having a different Doppler shift. The multicopy correlation operation is a time-frequency transformation of the received signal. Synthetic spectra are found by selection of spectral lines and concatenation, starting from the spectrum of the received signal. An inter-spectral product is computed, in other words by the product of each synthetic spectrum with the concatenated conjugate spectrum of the corresponding Doppler copy. A frequency-time transformation of the inter-spectral products is performed.

Abstract: The disclosure relates to a signal processing method for a towed linear antenna, notably to resolve right-left ambiguity, said antenna comprising a set of hydrophone multiplets each with n?3 hydrophones spread over a straight section of the longitudinal axis of said antenna, wherein the roll angle of each multiplet relative to the vertical is measured, the signals of said hydrophones and said roll angles are used to synthesize p?3 linear sub-antennas, then M azimuth channels are formed with each sub-antenna and 2 adaptive right-left channels are formed from said p sub-antennas for each direction corresponding to each azimuth channel. The invention resolves right-left ambiguity with optimal performance in detection and for long antennas.

Abstract: The invention relates to methods which make it possible to measure the Doppler shift of the echoes of a detection system. That is, the present invention modulates the frequency of the pulses of the transmissions of this system by a pseudohyperbolic function such that a restricted number of copies of the transmission signal can be used to perform the correlation operations on reception and to have them followed by an interpolation operation.