System engineering at the edge of a cabled ocean observatory

A cabled ocean observatory such as NEPTUNE Canada is a complex system of systems. Technologies include software, firmware, DC power systems, electrical and optical communication systems, subsea cable and connector design, pressure housings and material compatibility to pressure and salt water, as well as instrument transducers and control systems. These systems are designed and built by a variety of manufacturers, each of whom brings a different level of experience to the work. In addition, many of the instruments are development prototypes that are provided without the benefit of a long prototyping and qualification process. Once deployed, equipment must have a long operating life. The cost of a cruise and ROV intervention to maintain a piece of equipment will often exceed the cost of the equipment. Cost effective cruise planning requires that the state of the equipment to be maintained be known before going on site. The only means of diagnosing subsea equipment health is through the communications system via software interfaces. The information comes from a variety of simple measuring devices, selected by the engineering team on the basis of long life and necessity. This paper will present the case that all of the systems that make up a cabled ocean observatory must be closely intertwined for the observatory to succeed. Using the trial deployment of a NEPTUNE Canada instrument module on the VENUS observatory as an example, this paper will consider the issues for the system engineering team of integrating the observing instruments with the network and the control software..