Metadata Report for BODC Series Reference Number 1050264

• 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

SIMORC data access conditions

The data collated and held at BODC on behalf of the SIMORC project are restricted. However, the data will be available to download from the Official SIMORC Website, as part of the project protocol. The data set will initially include data from the oil companies TOTAL, Shell and BP.

Narrative Documents

RD Instruments 1200kHz Workhorse Sentinel Acoustic Doppler Current Profiler

Specifications

The manufacturer's specification document can be found here

Teledyne RDI Workhorse Sentinel 600 kHz Acoustic Doppler Current Profiler (ADCP)

The Workhorse Sentinel is a self-contained ADCP that can be used either on a mooring or mounted in the hull of a moving vessel. Its 4-beam design provides a redundant data source (in case of a blocked or damaged beam), an independent data quality measure (error velocity) and reduces the variance in data, thereby improving data reliability, quality and accuracy.

Real-time data can be transmitted to shore via a cable link or acoustic modem or they can be stored internally. Sensors for bottom tracking, pressure and directional wave measurements can be added to the instrument and a special casing is available for deeper applications.

Specifications

Further details can be found in the manufacturer's specification sheet.

BODC Processing

Data were received by BODC in CSV files. They were reformatted to QXF format using BODC transfer function 422. The following table shows how the variables within the files were mapped to the appropriate BODC parameter codes:

Following transfer to QXF, the data were screened using BODC's in-house visualisation software, EDSERPLO.

Originator's Data Processing

Data processing

Data were downloaded from the ADCPs using RD Instruments WinSc software. The current and wave data were separated by running RD Instruments WavesMon software and the wave data was imported into Matlab for the following processing.

• The record was truncated to exclude times pre and post deployment.
• Time was recorded in GMT.
• Data was adjusted from magnetic to true north using a magnetic variation of 1°6'E for the Sisi location and 1°7'E for the Peciko location, changing by 0°1'W per year.
• Attitude data were examined for the data from the 300 and 600kHz ADCPs and found to be within the instrument's operating range for the 600kHz instrument. Some of the 300kHz exceeded the 20° range, but the heading, speed and direction looked consistent so this data was not flagged.
• The beam intensity data were examined and showed the expected reduction in intensity with increasing range.
• The beam correlation data were also examined and where this fell below 64 for any of the 4 beams, all the data in this bin were flagged.
• Checks were run on the percentage good data. All ensembles where the number of two beam solutions exceeded 50% were flagged.
• Checks were run on error velocities. All velocities beyond a cut-off range of -20 to 20 cm.s^-1 were flagged.
• Checks were run for outliers in the speed, velocity north and velocity east data by comparing the median value to the centrepoint, allowing a tolerance of 10 cm.s^-1.

General Data Screening carried out by BODC

BODC screen both the series header qualifying information and the parameter values in the data cycles themselves.

Header information is inspected for:

• Irregularities such as unfeasible values
• Inconsistencies between related information, for example:
  • Times for instrument deployment and for start/end of data series
  • Length of record and the number of data cycles/cycle interval
  • Parameters expected and the parameters actually present in the data cycles
• Originator's comments on meter/mooring performance and data quality

Documents are written by BODC highlighting irregularities which cannot be resolved.

Data cycles are inspected using time or depth series plots of all parameters. Currents are additionally inspected using vector scatter plots and time series plots of North and East velocity components. These presentations undergo intrinsic and extrinsic screening to detect infeasible values within the data cycles themselves and inconsistencies as seen when comparing characteristics of adjacent data sets displaced with respect to depth, position or time. Values suspected of being of non-oceanographic origin may be tagged with the BODC flag denoting suspect value; the data values will not be altered.

The following types of irregularity, each relying on visual detection in the plot, are amongst those which may be flagged as suspect:

• Spurious data at the start or end of the record.
• Obvious spikes occurring in periods free from meteorological disturbance.
• A sequence of constant values in consecutive data cycles.

If a large percentage of the data is affected by irregularities then a Problem Report will be written rather than flagging the individual suspect values. Problem Reports are also used to highlight irregularities seen in the graphical data presentations.

Inconsistencies between the characteristics of the data set and those of its neighbours are sought and, where necessary, documented. This covers inconsistencies such as the following:

• Maximum and minimum values of parameters (spikes excluded).
• The occurrence of meteorological events.

This intrinsic and extrinsic screening of the parameter values seeks to confirm the qualifying information and the source laboratory's comments on the series. In screening and collating information, every care is taken to ensure that errors of BODC making are not introduced.

Project Information

System of Industry Metocean data for the Offshore and Research Communities (SIMORC)

The EU-funded SIMORC project is a collaborative effort between MARIS (Netherlands), BODC (UK), the International Association of Oil and Gas Producers (OGP) and IOC-IODE to provide a harmonised and quality controlled metocean data set from data collected by oil and gas producers, accessible through the SIMORC protocol.

Data Activity or Cruise Information

Data Activity

SIMORC Mooring Indonesia Sisi

The position of the mooring was 0.77141° S; 117.8059° E at a depth of 70 metres.

The mooring was deployed on behalf of TOTAL at Stupa, Indonesia and consisted of the following instruments.

Related Data Activity activities are detailed in Appendix 1

Cruise

Complete Cruise Metadata Report is available here

Fixed Station Information

Fixed Station Information

SIMORC: TOTAL Indonesia Sisi Fixed Station Document

This site is offshore of the Mahakam Delta, north of Balikpapan in the Makassar Strait. A mooring was deployed at this site.

The nominal position of this site is 0.77141° S; 117.8059° E with an approximate water depth of 70 metres.

Related Fixed Station activities are detailed in Appendix 2

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: Sisi

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

If you are interested in these series, please be aware we offer a multiple file download service. Should your credentials be insufficient for automatic download, the service also offers a referral to our Enquiries Officer who may be able to negotiate access.

Appendix 2: Indonesia Sisi

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

If you are interested in these series, please be aware we offer a multiple file download service. Should your credentials be insufficient for automatic download, the service also offers a referral to our Enquiries Officer who may be able to negotiate access.