Integrating in-situ chemical sampling with AUV control systems

The utility of autonomous underwater vehicles continues to expand as powerful new in-situ sensor technologies are developed for AUV operation. However, these analytical sensors are typically configured to collect and log data as independent payloads without the benefit of feedback from other payload sensors or vehicle navigation systems. This paper explores conceptual frameworks for integrating payload sensors in various degrees of real-time data assimilation and adaptive operation. Several of the challenges to coupling chemical sensor payloads in closed-loop architecture with acoustic, visual and navigation control systems are examined. Specific examples are provided as to how information sharing and coupled decision making processes may improve payload data interpretation and validation as well as increase the overall efficiency of AUV mission strategies. Data is presented from deployments of the Seabed submersible, a passively stable, hover-capable AUV designed for operation to 2000 meters. During these deployments the Seabed vehicle was arrayed with a payload of optical, acoustic, and chemical sensors to identify and map structures associated with ocean bottom methane sources on the Atlantic slope of North America. Results from these deployments are discussed and a collection of general principles is suggested for integration of biological and chemical sensors as payload with active feedback aboard AUVs. The authors conclude with suggestions for possible scientific applications that can be addressed using levels of technology presently available as well as how incremental advancements in AUV payload integration will present profound new opportunities to explore and understand our world.