SeaCycler
- Sub-Surface Moored Profiler with Two-Way Satellite Communication
- Sub-Surface Moored Profiler with Two-Way Satellite Communication
SeaCycler is a new mooring technology developed to provide multi-disciplinary oceanographic sampling using satellite communication for remote control and whole-mooring data recovery. This surface piercing profiler has no surface expression except when it pierces the surface to communicate and collect surface measurements.
Measurements in the near surface layer are very important for a wide range of applications, and yet they are very hard to obtain due to the difficulty in maintaining instruments in the extreme environmental conditions caused by high winds and waves. SeaCycler was designed to avoid this problem through intermittent profiling using an efficient winch design that conserves energy. The Autonomous Underwater Winch Profiler minimizes the residence time of the instruments in the upper layer, thus reducing the mechanical stresses imposed by environmental conditions.
SeaCycler cycles (or profiles) a sizable sensor suite (approx. 120 lbs in air, see photo at left) between a safe hiding depth and the air-sea interface. Up to seven user-configurable sensors are profiled to the surface from a depth of 150m. Sampling can be continuous throughout the profile (in either direction), occur at discreet depths by stopping and restarting the profile, or be event-triggered such as required for early-warning tsunami detection.
Data from these sensors (and others located deeper on the mooring) are communicated to shore via satellites through the Communication Float (see photo at right). The sampling schedule can be changed remotely without recovering the mooring. Satellite communication is established whenever the SeaCycler has surfaced, but it spends most of it’s time at a depth resistant to biofouling and unaffected by surface hazards such as ships, long-line fishing and storm-waves. If wave heights are excessive, an onboard computer aborts the profile at the upper safe damage-free depth and stores the data for upload on the next successful surfacing. Initial testing has demonstrated multiple satellite file transfers through 5.5m waves and the system has survived storm waves up to 10 meters.
SeaCycler is buoyant (1200 lbs in total) and replaces the sub-surface float on top of a conventional mooring. The photo at right shows the three major components laid out at the surface awaiting deployment of the anchor. The assembly occupies the upper 170m of the mooring and consists of three buoyant floats. The largest, known as the Mechanism Float (“MechFloat”, bottom of picture), is located deepest in the water column. It contains the majority of the buoyancy and an underwater winching system. Above that is the Instrument Float (“InstFloat”) which houses the scientific sensor suite and links to a small Communications Float (“CommFloat”, top of the picture) located at the top of the mooring. The InstFloat and CommFloat profile together towards the surface as the MechFloat pays out cable.
SeaCycler's Mechanism Float (underwater winch) breaks the surface during recovery
Daily 150m profiles over year-long deployments are made possible by SeaCycler’s unique ability to conserve energy while profiling. SeaCycler is designed for the open-ocean in water depths between 270m and 5000m. Its crush depth is 1000m and it has a 350m net profiling capability to compensate for mooring knockover in high water currents (150m typical + 200m reserve). The winch is driven by a novel compliant motor system which controls the motion of the profiling floats without the use of slip-rings or rotating seals to enhance reliability and provide operational robustness.SeaCycler Design Features:
- Conserves onboard power for numerous, long profiles
- 365 x 150m profiles are possible for year-long deployments
- Satellite communication for semi-real time data and remote control operation
- Open-ocean design suitable for deep water (5000m) sites
- Extra cable storage to compensate for mooring knockover
- 150m “hide-depth” for security and bio-fouling
- Surface avoidance when the risk of damage to hardware is likely
- Large instrument payload (120 lbs in air)
- Profile stops for discreet sampling
- Robust drive system (no rotating seals or slip-rings)
- Provides 1200 lbs buoyancy for mooring top support
- Simple straight-through cable routing – anchor to surface
- Inductive modem coupling to deeper-water instrumentation
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SeaCycler has been tested in a variety of locations and water depths. An early test took place in 1120 metres of water between October 2010 and Jan 2011.A third-generation prototype was built and tested in Canada at the Bedford Institute of Oceanography with SeaCycler Consortium partners from the USA (Scripps Institute of Oceanography), Germany (Leibniz Institute IFM-GEOMAR & University of Bremen) and England (National Oceanography Centre) and was deployed in 1100m of water between April 16 and May 26, 2011. During this deployment it collected 644 data profiles of the top 150m of the water column.
 The data collected by the SeaCycler can be seen here. This data was collected, processed and presented in graphical form by the SeaCycler development team, the National Data Buoy Center and the Integrated Science Data Management at Fisheries and Oceans Canada (DFO). Special thanks go to Christian Begler at Scripps Institution of Oceanography for his post-processing and presentation work. Displayed Date and Time in AST. |
Physical Specifications:
| CommFloat: | InstFloat: | MechFloat: | |
| Weight in Air | 40 lbs + | 510 lbs | 4070 lbs |
| Net Buoyancy | 12 lbs | 230 lbs | 970 lbs |
| Length | 60 in + | 98 in + | 160 in |
| Diameter | 5.3 in | 24 in | 55 in |
SeaCycler was designed with the following specifications in mind:
| Water depth of main mooring | 270m to 5000m |
| Instrument Float parking depth | 150m |
| Maximum subduction depth | 1000m |
| Profiling speed | 0.2 m/s to ~ 0.4 m/s (user defined) |
| Deployment duration | 1 year (365+ x 150m profiles) |
| Communication | 2-way telemetry at surface (Iridium, Freewave) + GPS fix |
| Deployment procedure | 'anchor last' |
| Special sampling | Sampling stops at user-defined depths for sensors with long time constants |
| Communication with deep mooring | Inductive link |
| Initial sensor suite | CTD, Oxygen (SBE-52/SBE-43), pCO2 (Pro-Oceanus - scheduled for next deployment), NO3 (Nortel Aquadopp - currently self-logging only) |
| Surface current | 200m of extra profiling cable is stored and available to allow the floats to reach the surface during mooring knockover events due to high water currents. |
“Rolls-Royce Canada Limited, Naval Marine” (formally “ODIM Brooke Ocean”) is a consortium member with license to manufacture SeaCycler (www.brooke-ocean.com).
For more information on the SeaCycler and its applications, please contact Rolls-Royce Naval Marine Canada.
SeaCycler was developed by the SeaCycler Consortium (seacycler.ifm-geomar.de), based on the ICYCLER under-ice moored profiler, originally developed by the Bedford Institute of Oceanography, Ocean Physics Division and the Department of Fisheries and Oceans Canada. SeaCycler is manufactured and sold by Rolls-Royce Naval Marine Canada under license. Visit the DFO ICYCLER website by clicking here.
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URL: http://www.brooke-ocean.com/seacycler.html (Last Updated: July 27, 2011)