Impact of underwater bandwidth and SNR on cross-correlation-based population estimation technique of fish and mammals

Abstract

Efficient population estimation of fish and mammals is one of the prerequisites of environmental monitoring and research. In order to overcome the limitations of conventional methods for population size estimation of fish and mammals, a cross-correlation based passive acoustic technique is proposed as an additional method. However, limited bandwidth of underwater channels poses a challenge during acquisition of fish signals with this technique. To overcome this problem, proper scaling is a mandatory task. The present study investigates scaling factors for chirp and grunt signals at 0–5 kHz underwater bandwidth. A low signal-to-noise ratio (SNR) is shown to be an impediment to obtain an accurate estimation. The present research concludes that estimation with minimum SNR of 26.02 dB performs similarly to estimation without noise.