From Data Buoys
Envirtech MKIII Data Buoys are tall, thin buoys that float upright in the water and are characterized by a small water plane area and a large mass. Because they tend to be stable ocean platforms, spar buoys are popular for making oceanographic measurements. In Envirtech ocean data acquisition systems, spar buoys are used to collect data from the sea bottom and to relay this data using satellites, such as Inmarsat or Iridium, to a control center on shore. The buoy assures a very stable platform for bidirectional communications to/ from the ocean bottom, and allows total remote control of deployed devices. Together with an Envirtech Tsunameter the MKIII is a reliable part of any marine tsunami warning system. The buoy survives to Cyclons (Beaufort 14-17 extend scale – checked with Typhoon Megi in 2010).
The Envirtech buoy MKIII is composed of three main parts:
- A subsurface pole;
- A float (cone + cylinder) in the middle;
- A turret on the top.
The main advantages of this configuration for specific data relay applications are the following:
- The lower pole provide a reliable mechanical support for the acoustic modems and related cables: the acoustic transducers can be mounted at a depth of least 5-6m to get a reliable acoustic link.
- The top, central part of the float can contain the battery and electronic unit with related connectors.
- The turret on the top allows the mounting of solar panels, the satellite modems and additional devices such as a Wi-Fi interface, meteorological station, etc.
- The hydrodynamics of the buoy are characterised by small tilt movements: this provides a vertical, stable platform to optimise the performance of the acoustic link between the buoy and the underwater module that transfers the data related to the
- tide and tsunami detection.
The buoy can be optionally supplied with further payloads such as:
- A complete meteorological station (single or double)
- An ADCP for multi-cell current data collection
- Water quality multi-parameter probe
- The Envirtech MKIII consists of rotationally molded, foam-filled polyethylene floats, and an AISI316 stainless steel structure.
- The MKIII has been built to remain operational during super typhoons, with sea conditions up to Beaufort 14. In 2010, the buoy proved its great strength when the super typhoon Megi crossed its mooring position in the South China Sea.
- The MKIII has a redundant payload. This means it has double CPUs, double acoustic modems and double satellite transceivers. Inmarsat miniC and iridium are standard communications systems but optional alternative payloads can be supplied for Beidou (only for Chinese end-users) and Insat.
- The buoy is also available in the ETD (Easy To Deploy) configuration with reduced dimensions of all metallic parts and powered by lithium batteries instead of solar panels.