Target parameter determination e.g. for ship or torpedo - using passive method to detect Doppler frequencies in active sonar reverberations from target emitting sound pulse

摘要

The doppler reverberation frequencies are derived from the frequency spectra of the reverberation and used to determine the target parameters. The maximum and minimum Doppler frequencies are determined. The target transmission frequency is determined from the average of the two values. - The speed of the target is determined by multiplying the speed of sound in water by the quotient of the difference between the maximum and minimum Doppler frequencies and twice the transmission frequency.