OOI Science Plan: Exciting Opportunities using OOI Data
RCA was initially planned with a Ring Topology, but industry professionals on the UW team recommended a Star Topology. The arguments for and against the two configurations are captured in the article, Comparison of Fiber-Optic Star and Ring Topologies for Electric Power Substation Communications (Scheer, 1999). Primary Nodes distribute power (8 kW) and bandwidth (10 Gbs) among secondary infrastructural elements, which includes 33,000 m of extension cables, junction boxes, instrumentation and moorings. Realtime communication to shore enables direct interaction with ports on the junction boxes and with individual instruments, allowing adjustment of sampling protocols (e.g., HD camera missions), and to monitor and respond to health and status of the network elements. A Science Interface Assembly (SIA) in six of the seven Primary Nodes houses five wet-mateable science ports with 1 gigabit Ethernet (GbE) and 375 V capabilities and two high bandwidth ports (10 GbE, 375 V) for network expansion. An important design decision was the use of wet-mate connectors from the oil industry on cables and junction boxes to optimize efficiency in operations. Another key element in the design to optimize efficiency is that the heavy (SIA) module can be recovered with a Remotely Operated Vehicle (ROV) hosted on a UNOLS ship, such that it does not require a cable laying ship from industry. Primary Nodes do not contain instrumentation and are used to convert 10 KVDC primary level voltage from the Shore Station to lower 375 VDC levels and distribute that power and communication to junction boxes distributed around each site. Secondary Nodes (junction boxes) are connected to the Primary nodes by extension cables and are designed to access specific experiments. Each junction box includes eight configurable ports that provide 12, 24, and 48 Volts DC at either 50 or 200 Watts of power. Pulse per second timing is available on all ports with ~10 μS accuracy. Communications from each instrument port are converted, if necessary, to Ethernet at 100 Mbps. All science data are timestamped at ~10 μS accuracy. Engineering circuitry in each node detects electrical failures of in-water instruments and allows shutting off of instruments as appropriate. Physically and logically
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separate data channels allow ultimate engineering control over all aspects of system operation. If a device were to fail in a way that disrupted normal network traffic, it can be isolated and powered down. Mission execution programs are written for individual platforms and instruments to automate sampling, turning on and off power etc. Key to the design of the underwater observatory was that the system be highly expandable with respect to power and bandwidth, allowing substantial future growth, which is now being realized. The secondary infrastructure (e.g. junction boxes and moorings) was designed and built by the University of Washington Applied Physics Laboratory (UW/ APL). This resulted in a lower cost than going with industry and provides significant and rapid response capabilities to refresh components due to rapidly expanding technologies. In addition, the junction boxes are rapidly configured to meet the growing requirements of the community (PI’s funded by NSF, NASA, ONR, Germany) to add new cabled instruments and platforms each with unique power and communication requirements. There are currently 17 PI-funded cabled instruments included on the RCA network.
B. Profiling Moorings A Profiling Mooring Workshop (Daly et al. 2008) was held in July, 2007 to: (1) assess the current status of profiling mooring capabilities, including development in progress; (2) compare the current capabilities to the program’s expectations and requirements for profiling moorings; and (3) provide recommendations for further development, where needed. Profiling platforms are among the infrastructure considered to be an essential component of the OOI facility. Profilers are critical to achieving the high vertical resolution sampling necessary to determine both episodic events and long-term trends over decades from the air-sea interface to the sea floor. A significant OOI goal is to resolve the strong vertical property gradients associated with phenomena, such as biological thin layers, inertial wave propagation, and mixed-layer deepening and entrainment. Profilers also are cost effective as they minimize the number of sensors needed to obtain a simultaneous water column 80
