Study of noise interfering with dolphin clicks

Abstract

Accurate assessment of dolphin numbers in the Ganga river is crucial for not only conservation but also for the environment. However, the methods used by the government agencies are based on human visualization. These methods are unreliable and also difficult to deploy for continuous monitoring of the dolphins. So, there is a need to develop a system which will be robust, automatic, and reliable to count, track, and analyze the dolphin activities. The dolphin counting system consists of an array of hydrophones which are used to capture dolphin clicks. For counting purpose, this array is required to be mounted on a boat for dragging at a certain speed which is greater than the speed of dolphins. During the movement of the boat, lot of noise is picked up by the hydrophones apart from dolphin clicks. The presence of noise causes the dolphin click detection really a challenging task. In this paper, the various sources of noise and reduction techniques are investigated and presented.