Metadata Report for BODC Series Reference Number 897227

• 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

RBR Ltd Depth Recorder Model DR-1050

Single channel data logger.

Manufacturer's specifications:
Case size: 230 mm x 38 mm
Material: Delrin (acetal copolymer); titanium (for up to 10,500 m)
Depth ratings: Delrin housing 10/20/50/100/200/500/740 m (dBar); titanium 1000/2000/4000/6000/10,000 m (dBar)
Accuracy: ±0.05% full scale
Resolution: <0.001% full scale
Time Constant: < 10 msec

The DR-1050 uses an internal Keller piezo-resistive strain gauge sensor (an absolute pressure sensor). Atmospheric pressure must be subtracted from the absolute pressure to obtain water depth. The standard depth sensors are calibrated at RBR to better than ±0.05% full scale. Using reliable semiconductor technology and a 316 stainless steel housing, the depth sensors are developed for long-term stability in harsh environments. This is also reflected in their operating temperature range of -40°C to 125°C. Typical depth hysteresis of the depth sensor is ±0.015%FS, and it has a response time of 0.1 msec.

Data are uploaded from the logger and processed using the RBR Windows Data Logger Software.

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

BODC Processing

Data were received by BODC in ASCII format files. For each instrument there is a file containing a pressure time series.

This series was reformatted to the internal QXF format using BODC transfer function 325. The following table shows how the variables within the file were mapped to the appropriate BODC parameter codes.

The deck pressure had not been measured, or removed from the data series, prior to submission of data to BODC. We thus derived a pressure offset from the instrument deployment pressure (calculated from deployment depth and latitude) and the first reading of the pressure time series. All water level recorders were bottom-mounted so the instrument depth was simply the depth of the seabed measured by the ship's echosounder at the time of deployment. The offset was applied to the entire series following the form: P_corr = P_orig - offset where P_corr is the corrected pressure and P_orig is the original pressure reading.

Following transfer to QXF, the data were screened using BODC's in-house visualisation software, EDSERPLO. Any data considered as suspect were flagged 'M'. Flags from the originator marking suspect data were retained during transfer and flagged 'L'.

Originator's Data Processing

Sampling Strategy

The depth recorder deployed in Loch Ewe had a sampling frequency of 60 readings per hour.

Data Processing

FRS applied the standard manufacturers' calibrations to all data, and produced ASCII files for submission to BODC. Data files were named according to the instrument code (752w).

Project Information

No Project Information held for the Series

Data Activity or Cruise Information

Data Activity

FRS bottom mounted depth recorder, Loch Ewe

The depth recorder (DR) was located at 57° 46.97' N, 005° 37.77' W in a nominal water depth of 8 m.

The DR was deployed on 17 July 2007 by Fisheries Research Services (FRS, now known as Marine Scotland Aberdeen Marine Laboratory) on cruise Glen Tarff 1907H (16 July 2007-20 July 2007) and recovered on 13 November 2007. Instrumentation details are contained in the following table.

Cruise

Complete Cruise Metadata Report is available here

Fixed Station Information

No Fixed Station Information held for the Series

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: