Acoustic modem for micro AUVs: design and practical evaluation

The recent development of small, cheap AUVs such as MONSUN and Hippocampus enables a plethora of applications for underwater inshore monitoring. Among these are the detection of pollution sources in ports, water-quality monitoring in lakes, and the support and protection of divers in context of disaster management. These tasks profit from online reporting and controlling as well as swarm interaction between the AUVs. For this purpose, communication is required. In this paper, we present a prototype of an acoustic modem that is (i) small enough to be carried by micro AUVs in the sub 10 L class, (ii) consumes little enough energy to not diminish operation times of its host, (iii) comes at an attractive unit cost of less than €600, and (iv) can reliably communicate at distances of 50m and more. Due to its modular build, the modem can be easily customized and is hence suitable as research platform to analyze, e.g., MAC and routing protocols. We present results of detailed real-world studies of its communication range, packet reception rate, and ranging accuracy.