Metadata Report for BODC Series Reference Number 643995

• Metadata Summary

• Problem Reports

• Data Access Policy

• Narrative Documents

• Project Information

• Data Activity or Cruise Information

• Fixed Station Information

• BODC Quality Flags

• SeaDataNet Quality Flags

Metadata Summary

Problem Reports

No Problem Report Found in the Database

Data Access Policy

Public domain data

These data have no specific confidentiality restrictions for users. However, users must acknowledge data sources as it is not ethical to publish data without proper attribution. Any publication or other output resulting from usage of the data should include an acknowledgment.

The recommended acknowledgment is

"This study uses data from the data source/organisation/programme, provided by the British Oceanographic Data Centre and funded by the funding body."

Narrative Documents

DATARING Datalogger Tide Gauge

The DATARING logger takes signals from Digiquartz pressure transducers and pressure operated gauges which are connected to the tidal pressure by a bubbler system. Float operated gauges can also supply a sea level signal to the datalogger. A number of sites also collect wind speed and direction data. The signals are processed to take account of water density, datum offset and calibration factors.

The data are averaged over a 15 minute period, with the centre points being o'clock, quarter past, half past, and quarter to. These readings are stored in internal memory and approximately 14 days can elapse before data are likely to be overwritten. The data can be accessed by POL and the Storm Tide Forecasting Service either locally or remotely over the telephone line. The data are retrieved on a weekly basis and appended onto the existing database, giving a continous record for each site.

Full and Mid Tide Bubbler Tide Gauge Systems

Full Tide Bubbler

The full tide bubbler system normally consists of two independent measuring points, unless a float gauge already exists, when this would form the second measuring system. The pressure points which are mounted underwater are similar in appearence to an inverted bucket with a copper nozzle mounted on the side. This nozzle is the actual measuring point.

A low flow of dry air (normally 7cm per min) is fed down an air tube to the top of the pressure point. When the air pressure in the line equals the pressure exerted by the column of water above it, then the excess air is released as bubbles through the copper nozzle. This means that the pressure in the air line is proportional to the weight of the water column.

Mid Tide Bubbler

The operation of the mid tide bubbler is similar to that of the full tide system (described above), except that the measuring point is mounted at the mid tide height. This means that the pressure point is only immersed for half of the tidal cycle. When the measuring point is exposed it can be accurately levelled into the geodetic network. Once this is accomplished the full tide pressure points can be fitted to match the tidal curve produced by the mid tide pressure point, thereby connecting them to the geodetic network.

Project Information

UK Tide Gauge Network

The national network of 'Class A' sea level gauges are deployed at 47 sites around the coast of the U.K.

The network was established after the serious flooding of the Thames estuary in 1953, which resulted from a violent storm in the North Sea.

The network sets out to obtain high quality tidal information through telemetry and provide warning of any possible flooding of coastal locations around the British Isles.

Data Activity or Cruise Information

No Data Activity or Cruise Information held for the Series

Fixed Station Information

Fixed Station Information

Dover (Kent) Site History

History Summary

Benchmark descriptions

ODN = Ordnance Datum Newlyn

Please also see document 83096

Datum information

For pre 1990 data, the heights have been adjusted by the data relative to ACD values, so that all data now refer to Admiralty Chart Datum.

Corrected Timing Errors

The table below lists the notified time errors for which corrections have been made (if the time error is positive the clock was fast, and if negative the clock was slow).

Quality Assessment

All data have been compared with the current Harmonic Constants library, and the residuals checked. Records have been visually inspected for spikes, datum shifts and timing errors.

Note: There are also a large number of small gaps (i.e. 1 or 2 data cycles) between 1959 and 1964.

• ASLVZZ01 = Sea Level, Unspecified Method (metres)
• ASLVZZ02 = Sea Level, Unspecified Method (metres)
• ASLVBG01 = Bubbler, Sea Level (metres)
• ASLVBG02 = Bubbler, Sea Level (metres)
• ASLVBH01 = Bubbler, Half Tide (metres)

Completeness index has been calculated for the primary channel only.

In November 1996, the gauge on channel one became useless and was removed.
The gauge that had been channel two, was moved to channel one and a temporary bubbler gauge was installed as the new channel two.
Channel one became the primary channel and channel two was the backup channel.
In May 1997, the gauges were removed and a new bubbler system was installed.
The new channel two became the primary channel and channel one the backup channel.

Missing and suspect data have been reported on the following day numbers.

Dover (Kent) Datum Information 1978-

Benchmark Relationships

• TGZ = Chart Datum = 3.67m below ODN
• TGZ = Chart Datum = 10.491m below TGBM
• TGZ = Chart Datum = 10.336m below Aux 1
• TGZ = Chart Datum = 12.193m below Aux 2
• TGZ = Chart Datum = 9.973m below Aux 3

Glossary

• TGZ = Tide Gauge Zero
• TGBM = Tide Gauge Benchmark
• Aux = Auxiliary Benchmark
• ODN = Ordnance Datum Newlyn
• CD = Chart Datum

Related Fixed Station activities are detailed in Appendix 1

BODC Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

SeaDataNet Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

Appendix 1: Dover

Related series for this Fixed Station are presented in the table below. Further information can be found by following the appropriate links.

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