The development of AUV strategies for multidisciplinary use

The Marine Environmental Research Lab for Intelligent Vehicles (MERLIN) operates an Explorer Autonomous Underwater Vehicle (AUV) that serves as a potential platform for ocean surveys over a broad range of disciplines. MERLIN undertook a four year development program to improve both the capacity and autonomy of the vehicle by acquiring multibeam, side-scan and sub-bottom profiling sonars and developing algorithms using these tools to improve the navigation of the vehicle as part of a project called Responsive AUV Localization and Mapping (REALM). The goal of REALM is to be able to pre-program the vehicle to both correct its own dead-reckoning position in a survey area and allow it to recognize Zones of Interest (ZOI). With such an improvement, programmed surveys could be modified in real time to allow the collection of additional detailed data in a ZOI. To develop an understanding of the types of data that might indicate a ZOI during a typical survey, a field program was developed for a site in Smith Sound, Newfoundland, Canada. Smith Sound was the site of the largest known overwintering inshore cod population in North America at a time when surrounding cod populations largely collapsed, creating interest in possible relationships between seabed properties and cod populations; the Sound is also of interest due to the potential presence of internal seiches and resonant tidal forcing; the area is the location of many documented, but unlocated shipwrecks; and, with depths over 200 m, is a region that is not easily explored without the use of technologies such as AUV's or other underwater vehicles. This paper presents the results of the preliminary Smith Sound survey, including an overview of the logistical planning aimed at collecting data with multidisciplinary interest. The individual data sets are presented, highlighting preliminary indications of ZOI for each topic of interest.