78
into external bladders varies their effective buoyancy allowing repeated ascents and
descents. To conserve power and avoid biological fouling in the sunlit near surface
ocean layers, the buoys keep a parking depth of about 2000 m and ascend at
approximately 10 day intervals. Following satellite positioning, the buoy transmits
its data package and descends to the parking depth. The ARGO system is a major
success for the global oceanic and atmospheric climatology community. Originally
developed as the Autonomous Lagrangian Circulation Explorer (ALACE) (Davis
et al. 1992), as of February 2017, 3962 ARGO floats are in operation throughout the
world ocean.
Modern coastal Lagrangian drifting buoys are equipped with GPS, and telemetry
capabilities using communication satellites or commercial land-based cellular networks. A widely used commercial system incorporates a small spherical buoy tethered to a diamond-shaped drogue constructed with a plastic tubing frame and a
synthetic fabric drogue. Electronics, including GPS, optional temperature reading,
a data logger, and satellite communications equipment, are housed within the buoy.
Battery life allows about 1 week operation. Larger commercial systems for more
extended deployment incorporate the holey sock design.
Low cost drifters incorporating consumer market GPS navigation and VHF radio
transmitter units can be built with readily available construction materials such as
closed-cell foams and PVC pipe. Such systems are useful for shorter term deployments with higher data return since they can be deployed and recovered from small
boats. VHF signal reception is however strictly in line-of-sight from the transmitter
so effective range from small boats is limited to a few kilometers for these
applications.
3.2.3 Autonomous Surface Vehicles
Satellite global navigation systems together with global telemetry now allow geolocation of remote surface platforms and two-way communication with such vehicles.
Solar, wind, and wave power in turn allow for extended vehicle autonomy. Several
innovative autonomous surface vehicles (ASV) are now available on the market, a
few being civilian offshoots of naval target drones. These AUVs can be operated
remotely but can also cover waypoint grids autonomously. Vessels can be singlehulled but the twin-hulled catamaran rig is favored for stability. The US National
Oceanic and Atmospheric Administration (NOAA) currently operates small monohull ASVs for inshore bathymetric surveys. Many have also found operational
application in inshore surveillance of ports and harbors and other high value assets.
Surveillance vehicles can be fitted with diesel engines but autonomy is poor. In
general, long-endurance vehicles make use of solar, wave, and/or wind power.
Among the most innovative and a potential harbinger of change is a wavepowered surface platform that has gained widespread recognition. Featuring a
surfboard- like low-profile single hull (3 m LOA), this unmanned surface vehicle
(USV) is propelled by an array of six movable winglet pairs mounted on a subsurface
3 Platforms for Coastal Ocean Observing
into external bladders varies their effective buoyancy allowing repeated ascents and
descents. To conserve power and avoid biological fouling in the sunlit near surface
ocean layers, the buoys keep a parking depth of about 2000 m and ascend at
approximately 10 day intervals. Following satellite positioning, the buoy transmits
its data package and descends to the parking depth. The ARGO system is a major
success for the global oceanic and atmospheric climatology community. Originally
developed as the Autonomous Lagrangian Circulation Explorer (ALACE) (Davis
et al. 1992), as of February 2017, 3962 ARGO floats are in operation throughout the
world ocean.
Modern coastal Lagrangian drifting buoys are equipped with GPS, and telemetry
capabilities using communication satellites or commercial land-based cellular networks. A widely used commercial system incorporates a small spherical buoy tethered to a diamond-shaped drogue constructed with a plastic tubing frame and a
synthetic fabric drogue. Electronics, including GPS, optional temperature reading,
a data logger, and satellite communications equipment, are housed within the buoy.
Battery life allows about 1 week operation. Larger commercial systems for more
extended deployment incorporate the holey sock design.
Low cost drifters incorporating consumer market GPS navigation and VHF radio
transmitter units can be built with readily available construction materials such as
closed-cell foams and PVC pipe. Such systems are useful for shorter term deployments with higher data return since they can be deployed and recovered from small
boats. VHF signal reception is however strictly in line-of-sight from the transmitter
so effective range from small boats is limited to a few kilometers for these
applications.
3.2.3 Autonomous Surface Vehicles
Satellite global navigation systems together with global telemetry now allow geolocation of remote surface platforms and two-way communication with such vehicles.
Solar, wind, and wave power in turn allow for extended vehicle autonomy. Several
innovative autonomous surface vehicles (ASV) are now available on the market, a
few being civilian offshoots of naval target drones. These AUVs can be operated
remotely but can also cover waypoint grids autonomously. Vessels can be singlehulled but the twin-hulled catamaran rig is favored for stability. The US National
Oceanic and Atmospheric Administration (NOAA) currently operates small monohull ASVs for inshore bathymetric surveys. Many have also found operational
application in inshore surveillance of ports and harbors and other high value assets.
Surveillance vehicles can be fitted with diesel engines but autonomy is poor. In
general, long-endurance vehicles make use of solar, wave, and/or wind power.
Among the most innovative and a potential harbinger of change is a wavepowered surface platform that has gained widespread recognition. Featuring a
surfboard- like low-profile single hull (3 m LOA), this unmanned surface vehicle
(USV) is propelled by an array of six movable winglet pairs mounted on a subsurface
3 Platforms for Coastal Ocean Observing