The Development of a Broadband Hydrophone System for Comparison with a Narrow Band System

Abstract

Governments have collaborated with community groups, NGOs, individuals, and business organizations in protecting endangered animal species. Scientists depend on advanced acoustic tracking technologies in examining animal behaviors within their natural habitats. Scientists consider Hector and Maui dolphins as endangered and rare subspecies requiring protection from human activities and climate change. Specifically, human activities like recreation, fishing, and ocean pollution have caused a significant decline in these dolphins’ populations. As a result, marine biologists have developed underwater acoustic sensors to examine the presence and behaviors of dolphins within the New Zealand coastline. New acoustic detection technologies utilize designs that address uniqueness in the dolphins’ ultrasonic pulses and performance. Hence, we intended to develop a hydrophone system that effectively detects Hector’s/Māui dolphins’ NBHF echolocation clicks. The experimental research entails developing and designing a broadband hydrophone system to enhance the tracking process for Hector and Maui dolphins. The hydrophone system was designed to sense the NBHF echolocation clicks of these dolphin subspecies, which is within a 120-125 kHz frequency range. The Altium Designer was utilized in designing the PCB, which was eventually printed in China. The printed PCB was tested using the Ltspice (stage 1), using an oscilloscope and a function generator (stage 2), and using a transducer in a submerged state (stage 3). A graphical representation of frequency output allowed the researcher to make an inference about the PCB’s performance. The LTspice software indicated that the developed PCB detected a frequency range of 100hz-150kHz and an intensity of 50 dB-52 dB. The test using a function generator and an oscilloscope indicated that the PCB detected the generated frequency efficiently. The last test phase indicates that Teledyne Reson TC4013-4 is inaccurate frequencies below 130kHz. The designed broadband hydrophone system detects frequencies in the 100hz150kHz range. The broadband hydrophone system is effective in detecting frequencies within the 120-125 kHz range. The experimental research indicates that the broadband system can detect NBHF echolocation clicks generated by Hector/Maui dolphins.