Many coastal and offshore construction activities require the driving of piles into the seabed, either using impact or vibratory pile drivers. Impact pile driving produces an intense impulsive underwater noise that has been associated with fish deaths at very short range, whereas vibratory pile driving produces a lower level continuous noise. Because of the high sound levels involved, noise fro...

Abstract For pulse compression characteristics and not easily affected by noise, linear frequency modulation signal are widely used in underwater acoustic communication. This paper analyzes the characteristics of hyperbolic frequency modulation signal over underwater acoustic channels. Compared with linear frequency modulation signal, hyperbolic frequency modulation has the same performance of ...

A highly efficient ultrasonic biotelemetry system would be desired to the ocean having a high underwater ambient noise that is especially from the temperate zone to the tropics. The four parameters were defined as the estimated factors for pinger system, long distance transmitting, battery life, pinger size and ability of recognition. The four parameters of the pinger were analyzed and investig...