The PI requests funding to develop an autonomous surface craft (ASC) SCOAP as a sampling platform for material transport rates and pathways. In this project a mobile platform for interdisciplinary sampling (the Surveying Coastal Ocean Autonomous Profiler, SCOAP) will be developed by redesigning and enhancing an available ASC. The enhancements include maximizing its seaworthiness, lengthening the duration of unattended deployments, and making it capable of safe marine operations in waterways with heavy vessel traffic, fixed and mobile fishing activity, and vandalism risks. SCOAP has potential to substantially advance the ability of coastal oceanographers to measure and investigate material transport processes. It can host suitable sensors to detect any parameter, and simultaneously measures quantities from multiple disciplines, so will help oceanographers from different areas of expertise integrate their studies.
The broader impacts would be a new autonomous multi-sensor vehicle that can provide long-term measurements in the coastal ocean. This effort has the potential to develop a significant new tool for studying a variety of coastal processes. The project includes graduate and undergraduate students for the engineering development and field work.
This project was an initial exploration of the potential for an autonomously operating robotic boat to advance oceanographic field sampling capabilities in coastal marine areas (the continental shelf and relatively large/deep estuaries). These waters provide a broad variety of services and essential resources to society and are recognized for their economic importance. Scientific understanding of processes that influence the health, quality, and safety of such coastal and estuarine waterbodies is constrained in major ways by our limited field measurement capabilities. Rates and pathways of material transport (the transport of water and waterborne materials, for example pollutants, fish larvae, suspended sediments, etc) in these systems are typically poorly known because available technologies for gathering oceanographic observations are not capable of providing the needed information, too costly to operate at the sustained levels required, or both. A robotic boat was designed, built, and demonstrated as a general platform for cost-effective oceanographic field measurement collection in coastal waters, with emphasis on enabling material transport measurements. First, available platforms suitable for oceanographic projects were assessed; they ranged from traditional moorings and research vessel surveys, to newer subsurface devices like gliders and propeller-driven vehicles, and included existing robotic surface craft. The conclusion was that an autonomous boat larger than existing options would have strong potential, as compared to available alternatives, to (a) cost-effectively achieve needed improvements in spatial and temporal coverage and resolution, (b) increase efficiencies by simultaneously measure a broader range of oceanographic conditions (spanning physical, chemical, biological and geological variables), and (c) be less vulnerable to challenges presented by heavy vessel traffic, fixed and mobile fishing gear, and vandalism. The boat design was based on enlarging an existing robotic catamaran to make it sufficiently seaworthy for open coastal waters and able to host larger energy reserves. The vessel speed range was determined by evaluating how often spatial coverage needs to be repeated during surveys to sample material transport. The goal of long endurance (up to a month unattended) led to use of a hybrid diesel-electric energy system. The boat can host and provide power for many oceanographic sensors. Because the main goal in this project was demonstrating the platform, it has so far only been equipped with one sensor, a device that measures water circulation patterns and facilitates estimates of water volume transport. The capabilities of the catamaran were exercised in a series of incrementally more challenging field deployments attended by an accompanying research vessel. These tests were initially in the protected waters of Allen Harbor, North Kingstown, Rhode Island then later in the more exposed waters of Upper West Passage, Narragansett Bay. The results suggest the design meets the seaworthiness and endurance needs. On-board navigation software with autonomy capabilities was adapted to the vessel and demonstrated on the water. Planning and preparation for a future deployment, in which unattended operations are to be demonstrated and a survey is to be completed in the open coastal waters of Rhode Island Sound, is mostly complete so a future project will be able to straightforwardly pursue these next stages of testing. Because coastal and estuarine settings commonly have heavy vessel traffic, many features of the boat design are oriented towards enabling safe unattended operation in crowded waterways. Guidance from the Coast Guard colleagues on operation of unmanned vessels was followed closely. The design includes lighting and markings to make other mariners aware there is no human operator on board. An approach for planning unattended operations was developed: they are to occur only along a designated sampling line that has been identified in cooperation with the Coast Guard, and made known to other mariners, well in advance. On-board navigation software that is sufficiently sophisticated to allow for future development of collision avoidance maneuvers, based on automated sensors that detect other vessels, was implemented. Initial tests of basic collision avoidance performance were completed. The field deployments provided evidence that the boat can collect useful new oceanographic observations. Water circulation patterns in Upper West Passage of Narragansett Bay were measured and analyzed, leading to improved understanding of water transports there. Two graduate students were trained in both oceanographic analysis techniques and robotics technologies. Finally, a project website (www.po.gso.uri.edu/~codiga/scoap/SCOAP.htm) uses photos, diagrams, videos, and graphics of oceanographic findings to present more detailed explanations of the motivation for the boat, its design, the field deployment results, and scientific outcomes.