E-SURFMAR definitions

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This page is dedicated to the E-SURFMAR definitions of terms used in the documentation.

VOS ships

Conventional VOS

  • Ship or platform recruited by a National Meteorological Service to manually collect observations which are normally reported using the ship own transmission equipment

Automatic Weather Station (AWS)

  • In the case of VOS, an integrated shipborne system for automatically collecting data measured by a number of sensors and for transmitting such data ashore normally using a dedicated transmission system.

Complex AWS

  • An AWS which additionally permits observers to add visual meteorological or oceanographic observations prior to data transmission using data entry display software.

Basic AWS

  • An AWS station which doesn't include a facility for adding visual observations and which incorporates a reduced number of sensor measurements. Such AWS will usually be independent of the host ships systems (other than power supply) and can generally be considered as 'plug and play' systems

Manned observations

  • Observations which are carried out by ships observing officers (or by other seagoing or offshore platform personnel) and which are derived visually from meteorological or oceanographic instruments, or from direct visual observations

Visual observations

  • Meteorological or oceanographic observations which are carried out by ships observing officers (or by other seagoing or offshore platform personnel) and which typically include observations of sea state, visibility clouds, present and past weather etc.

Automated observations

  • Measurements derived and collected by AWS sensors.

Active VOS

  • A VOS which has reported at least two observations during a given time period (e.g. a month or a year)


Data Buoys

Buoy period

  • The operational period for a buoy. In practice there is only one buoy period record for a drifting buoy unless it is being refurbished (or redeployed at another location after displacement, e.g. after fishing vessel pickup). For moored buoys we have as many buoy periods as periods of the buoy operations with no human intervention. In other words, whenever maintenance is being done on a moored buoy we have to create a new buoy period record.

Operational buoy

  • Drifting buoy: reporting at least air pressure onto GTS
  • Moored buoy: ...

Operational lifetime

  • Drifting buoy: time length of a buoy period, from deployment date to the GTS out date when the buoy ends its buoy period due to technical failure, battery exhaustion, beach, pick up, early recovery, accidents and vandalism.

Technical failure

  • The buoy ends its operational period due to technical failure.

Battery exhaustion

  • The buoy ends its operational period due to battery exhaustion.

Beach

  • The buoy reaches the shoreline and is washed a shore.

Pick up

  • Not voluntary pick up from the sea e. g. done by fisherman

Early recovery

  • Voluntary pick up, e.g. buoy testing.

Accident

  • failure caused by sources outside the buoy which the buoy is not design to withstand, e. g. the parachute no not open during air deployment due to technical failure of the parachute, or the buoy is crushed between containers on a ship before deployment, etc.

Vandalism

  • damage on the buoy made on purpose

Early failure

  • Buoy failure within 30 days after deployment.
  • Is it necessary to define this term in more details? e.g. that early failure because of the way it was deployed (methods not recommended from the buoy manufacturer or accidents) that makes the buoy fail and not due to a weakness with buoy? (see comments under Calculation of average lifetime)

Lifetime of a buoy type/model

  • Arithmetic average of the operational lifetime of all buoys within the group that ends its operational period due to technical failure and battery exhaustion.

Operational lifetime of a buoy type/model

  • Arithmetic average of the lifetime of all buoys within the group except buoys being early recovered.

Calculation of average lifetime for buoys that ceased to operate

  • NB! A buoy that is not transmitting AP (AP sensor has failed), but is in other way functioning (reporting all other kinds of data), is defined as NOT OPERATING. In calculation of average lifetime for buoys that ceased to operate these buoys must be included.
  • ? Consequent labelling of EGOS buoys in respect of time. Is the buoy defined as an EGOS buoy before deployment? Can one make a definition that clarifies which buoys that is taken into account, e.g. to avoid that sometimes the buoys that fail immediately after deployment is not taken into account depending on who is doing the registrations and calculations. Maybe there are incidents where it is clearly the way it was deployed that makes the buoy fail and not due to a weakness with buoy. Could these cases be identified? Would it be right to exclude these buoys from the calculation of average lifetime?
  • Other cases that needs to be clarified?


Communications

Real time mode data

  • Data which are sent immediately after the observation time and inserted onto the GTS soon thereafter - typically within one hour to meet model cut-off time limits.

Delayed mode data

  • The original or raw data collected by, or transmitted from, a marine observing platform. In the case of an observing ship this would normally be the log files which are stored in the ships electronic logbook software for subsequent download, and in the case of a drifting buoy this would normally be the raw transmitted Argos or iridium data prior to data processing


References

  • Hageberg, A. A (2003): Additional specification of a new relational meta database for EGOS and other DBCP Action groups, CMR-03/A10020