Low-Power Level-Crossing Rate-Based Diver Detection System

The sea houses some of humanity's most important economic infrastructure and cultural heritage, most of which lies unprotected from divers seeking to pillage it. Passive acoustic diver detection methods have enabled diver detection at much lower costs and power requirements than traditional active sonar systems. However, none of the passive acoustic detection systems developed thus far are capable of autonomous operation without the need for external power supplies and processing systems. In this paper, a low-power sensor node for diver detection based on a level-crossing rate detector and an STM32L0 microcontroller is proposed. The proposed system, consuming only 57.1 μW, is shown to achieve a detection accuracy of 94.6 % on the used dataset, compared to an accuracy of 98% achieved by a reference method requiring 4 orders of magnitude more operations to implement.