Population size estimation of chirp and grunt generating fish and mammals using cross-correlation based technique with three acoustic sensors

Abstract

Passive acoustic monitoring has the potential to be a useful tool for population estimation of sound-producing fish and mammals (mostly whales). Previous work on population estimates of callers employed a simple cross-correlation technique with recordings from two acoustic sensors, and the current work extends the technique to two configurations of a 3-acoustic sensors array using two different sounds, i.e., chirps which is commonly generated by damselfish (Dascyllus aruanus), humpback whales (Megaptera novaeangliae), dugongs (Dugong dugon) etc., species, and grunts which is commonly generated by Japanese gurnard (Chelidonichthys kumu), Grey gurnard (Eutrigla gurnardus), gulf toadfish (O. beta), etc., species. We compared simulated results from this technique with values determined by theoretical approach. We have found that an increasing number of cross-correlation function (CCF) provide better results using this technique. However, the technique has some limitations including negligence of multipath interference, assuming the delays to be integer.