Metadata Report for BODC Series Reference Number 897239


Metadata Summary

Data Description

Data Category Offshore sea floor pressure series
Instrument Type
NameCategories
RBR DR-1050 depth recorder  sea level recorders
Instrument Mounting fixed benthic node
Originating Country United Kingdom
Originator Ms Sarah Hughes
Originating Organization Fisheries Research Services Aberdeen Marine Laboratory (now Marine Scotland Aberdeen Marine Laboratory)
Processing Status banked
Project(s) -
 

Data Identifiers

Originator's Identifier 753/W
BODC Series Reference 897239
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2007-07-18 13:31
End Time (yyyy-mm-dd hh:mm) 2007-11-14 11:45
Nominal Cycle Interval 60.0 seconds
 

Spatial Co-ordinates

Latitude 57.85517 N ( 57° 51.3' N )
Longitude 5.68500 W ( 5° 41.1' W )
Positional Uncertainty 0.05 to 0.1 n.miles
Minimum Sensor Depth 14.0 m
Maximum Sensor Depth 14.0 m
Minimum Sensor Height 0.0 m
Maximum Sensor Height 0.0 m
Sea Floor Depth 14.0 m
Sensor Distribution Fixed common depth - All sensors are grouped effectively at the same depth which is effectively fixed for the duration of the series
Sensor Depth Datum Instantaneous - Depth measured below water line or instantaneous water body surface
Sea Floor Depth Datum Instantaneous - Depth measured below water line or instantaneous water body surface
 

Parameters

BODC CODE Rank Units Short Title Title
AADYAA01 1 Days Date(Loch_Day) Date (time from 00:00 01/01/1760 to 00:00 UT on day)
AAFDZZ01 1 Days Time(Day_Fract) Time (time between 00:00 UT and timestamp)
PREXPS01 1 Decibars MeasPress_SL Pressure (measured variable) exerted by the water body by fixed in-situ pressure sensor and corrected to read zero at sea level
 

Definition of Rank

  • Rank 1 is a one-dimensional parameter
  • Rank 2 is a two-dimensional parameter
  • Rank 0 is a one-dimensional parameter describing the second dimension of a two-dimensional parameter (e.g. bin depths for moored ADCP data)

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.

Original parameter name Original Units Description BODC Parameter Code BODC Units Comments
Time DD/MM/YYYY HH:MI date and time AADYAA01 + AAFDZZ01 day number and day fraction GMT Conversion by transfer
P decibars Pressure PREXPS01 decibars  

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 (753w).


Project Information


No Project Information held for the Series

Data Activity or Cruise Information

Data Activity

Start Date (yyyy-mm-dd) 2007-07-18
End Date (yyyy-mm-dd) 2007-11-14
Organization Undertaking ActivityFisheries Research Services Aberdeen Marine Laboratory (now Marine Scotland Aberdeen Marine Laboratory)
Country of OrganizationUnited Kingdom
Originator's Data Activity Identifier753w
Platform Categoryfixed benthic node

FRS bottom mounted depth recorder, Loch Ewe

The depth recorder (DR) was located at 57° 51.31' N, 005° 41.10' W in a nominal water depth of 14 m.

The DR was deployed on 18 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 14 November 2007. Instrumentation details are contained in the following table.

Instrument type Serial Number Deployment start Deployment end Instrument depth (m) Comments
RBR Data Logger DR-1050 13557 2007-07-18 2007-11-14 14  

Cruise

Cruise Name 1907H
Departure Date 2007-07-16
Arrival Date 2007-07-20
Principal Scientist(s)John Beaton (Fisheries Research Services Aberdeen Marine Laboratory)
Ship Glen Tarff

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:

Flag Description
Blank Unqualified
< Below detection limit
> In excess of quoted value
A Taxonomic flag for affinis (aff.)
B Beginning of CTD Down/Up Cast
C Taxonomic flag for confer (cf.)
D Thermometric depth
E End of CTD Down/Up Cast
G Non-taxonomic biological characteristic uncertainty
H Extrapolated value
I Taxonomic flag for single species (sp.)
K Improbable value - unknown quality control source
L Improbable value - originator's quality control
M Improbable value - BODC quality control
N Null value
O Improbable value - user quality control
P Trace/calm
Q Indeterminate
R Replacement value
S Estimated value
T Interpolated value
U Uncalibrated
W Control value
X Excessive difference

SeaDataNet Quality Control Flags

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

Flag Description
0 no quality control
1 good value
2 probably good value
3 probably bad value
4 bad value
5 changed value
6 value below detection
7 value in excess
8 interpolated value
9 missing value
A value phenomenon uncertain