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Metadata Report for BODC Series Reference Number 752011


Metadata Summary

Data Description

Data Category Currents -subsurface Eulerian
Instrument Type
NameCategories
Teledyne RDI Ocean Surveyor 75kHz vessel-mounted ADCP  current profilers
Instrument Mounting research vessel
Originating Country United Kingdom
Originator -
Originating Organization National Oceanography Centre, Southampton
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) Oceans 2025
 

Data Identifiers

Originator's Identifier SUR32107
BODC Series Reference 752011
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2007-07-31 12:01
End Time (yyyy-mm-dd hh:mm) 2007-08-01 11:31
Nominal Cycle Interval 300.0 seconds
 

Spatial Co-ordinates

Start Latitude 59.41833 N ( 59° 25.1' N )
End Latitude 59.47683 N ( 59° 28.6' N )
Start Longitude 18.71567 W ( 18° 42.9' W )
End Longitude 19.71750 W ( 19° 43.1' W )
Positional Uncertainty 0.0 to 0.01 n.miles
Minimum Sensor or Sampling Depth 13.0 m
Maximum Sensor or Sampling Depth 957.0 m
Minimum Sensor or Sampling Height -
Maximum Sensor or Sampling Height -
Sea Floor Depth -
Sea Floor Depth Source -
Sensor or Sampling Distribution Sensor fixed with measurements made at multiple depths within a fixed range (e.g. ADCP) - The sensor is at a fixed depth, but measurements are made remotely from the sensor over a range of depths (e.g. ADCP measurements)
Sensor or Sampling Depth Datum Instantaneous - Depth measured below water line or instantaneous water body surface
Sea Floor Depth Datum -
 

Parameters

BODC CODERankUnitsTitle
DBINAA010MetresDepth (spatial coordinate) of ADCP bin relative to water surface {bin depth} in the water body
AADYAA011DaysDate (time from 00:00 01/01/1760 to 00:00 UT on day)
AAFDZZ011DaysTime (time between 00:00 UT and timestamp)
ACYCAA011DimensionlessSequence number
ALATGP011DegreesLatitude north relative to WGS84 by unspecified GPS system
ALONGP011DegreesLongitude east relative to WGS84 by unspecified GPS system
APEWGP012Centimetres per secondEastward velocity of measurement platform relative to ground surface by unspecified GPS system
APNSGP012Centimetres per secondNorthward velocity of measurement platform relative to ground surface by unspecified GPS system
ASAMSP002DecibelsSignal return amplitude from the water body by shipborne acoustic doppler current profiler (ADCP) beam 1
ASAMSP022DecibelsSignal return amplitude from the water body by shipborne acoustic doppler current profiler (ADCP) beam 2
ASAMSP032DecibelsSignal return amplitude from the water body by shipborne acoustic doppler current profiler (ADCP) beam 3
ASAMSP042DecibelsSignal return amplitude from the water body by shipborne acoustic doppler current profiler (ADCP) beam 4
LCEWAS012Centimetres per secondEastward velocity of water current (Eulerian measurement) in the water body by shipborne acoustic doppler current profiler (ADCP)
LCNSAS012Centimetres per secondNorthward velocity of water current (Eulerian measurement) in the water body by shipborne acoustic doppler current profiler (ADCP)
LERRAS012Centimetres per secondError velocity of water current in the water body by shipborne acoustic doppler current profiler (ADCP)
LREWAS012Centimetres per secondEastward velocity of water current relative to moving platform in the water body by shipborne acoustic doppler current profiler (ADCP)
LRNSAS012Centimetres per secondNorthward velocity of water current relative to moving platform in the water body by shipborne acoustic doppler current profiler (ADCP)
LRZAAS012Centimetres per secondUpward velocity of water current in the water body by shipborne acoustic doppler current profiler (ADCP)

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

Open Data supplied by Natural Environment Research Council (NERC)

You must always use the following attribution statement to acknowledge the source of the information: "Contains data supplied by Natural Environment Research Council."


Narrative Documents

RD Instruments- Ocean Surveyor 75kHz Vessel mounted ADCP.

Long-Range Mode
Vertical Resolution Cell Size3 Max. Range (m)1 Precision (cm/s)2
8m 520 - 650 30
16m 560 - 700 17
High-Precision Mode
Vertical Resolution Cell Size3 Max. Range (m)1 Precision (cm/s)2
8m 310 - 430 12
16m 350 - 450 9

1 Ranges at 1 to 5 knots ship speed are typical and vary with situation.
2 Single-ping standard deviation.
3 User's choice of depth cell size is not limited to the typical values specified.

Profile Parameters

  • Velocity long-term accuracy (typical): ±1.0%, ±0.5cm/s
  • Velocity range: -5 to 9m/s
  • # of depth cells: 1 - 128
  • Max ping rate: 0.7

Bottom Track

Maximum altitude (precision <2cm/s): 950m

Echo Intensity Profile

Dynamic range: 80dB
Precision: ±1.5dB

Transducer and Hardware

Beam angle: 30°
Configuration: 4-beam phased array
Communications: RS-232 or RS-422 hex-ASCII or binary output at 1200 - 115,200 baud
Output power: 1000W

Standard Sensors

Temperature (mounted on transducer)

  • Range: -5° to 45°C
  • Precision: ±0.1°C
  • Resolution: 0.03°

Environmental

Operating temperature: -5° to 40°C (-5° to 45°C)*
Storage temperature: -30° to 50°C (-30° to 60°C)*

*later instruments have greater range.

Web Page

Further details can be found on the manufacturer's website or in the specification sheet

Instrument Description

Water velocities were measured using a vessel mounted RDI Ocean Surveyor 75 kHz ADCP (VMADCP) located at approximately 5 m depth. Data were logged using RDI software VmDAS v1.43.19. Heading difference (used for correction of current velocities) was derived from two gyro compasses and BestNav GPS system. Position and ship velocities were derived from a single antenna GPS receiver (BestNav). Further information on instrumentation can be found in the cruise report on pages 87-88 and on p135.

BODC Processing

The data arrived at BODC in 29 PSTAR format files (nomenclature = sur321##.abs) representing all the data collected during water tracking mode. These were reformatted to the internal QXF format using BODC transfer function 389. The following table shows how the variables within the PSTAR files were mapped to appropriate BODC parameter codes:

Originator's Variable Units Description BODC Parameter Code Units Comment
bindepth m Depth relative to the sea surface DBINAAS01 m  
evelcal cm s-1 Eastward current velocity measured by VMADCP (field calibrated) LREWAS01 cm s-1 Relative to ship's movement
nvelcal cm s-1 Northward current velocity measured by VMADCP (field calibrated) LRNSWAS01 cm s-1 Relative to ship's movement
velvert cm s-1 Upward current velocity LRZAAS01 cm s-1  
velerr cm s-1 Current velocity error LERRAS01 cm s-1  
intense1 % Beam strength ASAMSP00 %  
intense2 % Beam strength ASAMSP02 %  
intense3 % Beam strength ASAMSP03 %  
intense4 % Beam strength ASAMSP04 %  
good3bm % Notifies when 3 beam solution used to generate velocities - - Used for screening purposes - not transferred
verr % Unknown channel - - Unknown - not transferred
2+bmbad % % of pings where >1 beam bad - - Used for screening purposes - not transferred
good4bm % Notifies when 4 beam solution used to generate velocities - - Used for screening purposes - not transferred
ve cm s-1 Eastward velocity of ship by unspecified GPS APEWGP01 cm s-1  
vn cm s-1 Northward velocity of ship by unspecified GPS APNSGP01 cm s-1  
absve cm s-1 Absolute eastward current velocity LCEWAS01 cm s-1 Corrected for ship's movement
absvn cm s-1 Absolute northward current velocity LCNSAS01 cm s-1 Corrected for ship's movement
lat degrees Latitude north by unspecified GPS ALATGP01 degrees  
lon degrees Longitude north by unspecified GPS ALONGP01 degrees  
distrun Km Distance run - - Can be derived from lat and lon - not transferred

The reformatted data were visualised using the in-house EDSERPLO software. Suspect data were marked by adding an appropriate quality control flag. Missing data were marked by setting the data to an appropriate absent data value and absent data quality control flag.

Originator's Data Processing

Sampling Strategy

The VMADCP ran continuously throughout the cruise and was configured to sample over 60 bins of 16 m depth at 300 second intervals. The blank beyond transmit was 8 m and the first bin depth was 13 m. Data were reduced to 5 minute ensembles. The instrument was operated in water tracking mode with the exception of the cruise start1 when the bottom was shallow enough (<1000 m) to provide calibration of the instrument. Further information on sampling strategy can be found in the cruise report on p135.

1Please note that contrary to the cruise report, calibration was established at the beginning of the cruise only.

Originator's Data Processing

Logged data were transferred daily (approximately) to the PSTAR processing system where resulting files were read into PSTAR format, calibrated, corrected for the ship's movement and quality controlled using NOCS-generated Unix scripts. Full processing details2 can be found in the cruise report from p135.

2Please note that ashtech a-ghdg (on p136) refers to the heading difference calculated by Ashtech ADU-2 heading minus gyro compass heading. Further information on a-ghdg creation by Unix script ashexec2 can be found on p130 of the cruise report.

Field Calibrations

Calibration was obtained in bottom track mode with an offset angle = 0°.

    Φ (misalignment angle) = -59.4636°
    A (scaling factor) = 1.0019

Further information on calibration of the VMADCP can be found on p135 of the cruise report.


Project Information

Oceans 2025 - The NERC Marine Centres' Strategic Research Programme 2007-2012

Who funds the programme?

The Natural Environment Research Council (NERC) funds the Oceans 2025 programme, which was originally planned in the context of NERC's 2002-2007 strategy and later realigned to NERC's subsequent strategy (Next Generation Science for Planet Earth; NERC 2007).

Who is involved in the programme?

The Oceans 2025 programme was designed by and is to be implemented through seven leading UK marine centres. The marine centres work together in coordination and are also supported by cooperation and input from government bodies, universities and other partners. The seven marine centres are:

  • National Oceanography Centre, Southampton (NOCS)
  • Plymouth Marine Laboratory (PML)
  • Marine Biological Association (MBA)
  • Sir Alister Hardy Foundation for Marine Science (SAHFOS)
  • Proudman Oceanographic Laboratory (POL)
  • Scottish Association for Marine Science (SAMS)
  • Sea Mammal Research Unit (SMRU)

Oceans2025 provides funding to three national marine facilities, which provide services to the wider UK marine community, in addition to the Oceans 2025 community. These facilities are:

  • British Oceanographic Data Centre (BODC), hosted at POL
  • Permanent Service for Mean Sea Level (PSMSL), hosted at POL
  • Culture Collection of Algae and Protozoa (CCAP), hosted at SAMS

The NERC-run Strategic Ocean Funding Initiative (SOFI) provides additional support to the programme by funding additional research projects and studentships that closely complement the Oceans 2025 programme, primarily through universities.

What is the programme about?

Oceans 2025 sets out to address some key challenges that face the UK as a result of a changing marine environment. The research funded through the programme sets out to increase understanding of the size, nature and impacts of these changes, with the aim to:

  • improve knowledge of how the seas behave, not just now but in the future;
  • help assess what that might mean for the Earth system and for society;
  • assist in developing sustainable solutions for the management of marine resources for future generations;
  • enhance the research capabilities and facilities available for UK marine science.

In order to address these aims there are nine science themes supported by the Oceans 2025 programme:

  • Climate, circulation and sea level (Theme 1)
  • Marine biogeochemical cycles (Theme 2)
  • Shelf and coastal processes (Theme 3)
  • Biodiversity and ecosystem functioning (Theme 4)
  • Continental margins and deep ocean (Theme 5)
  • Sustainable marine resources (Theme 6)
  • Technology development (Theme 8)
  • Next generation ocean prediction (Theme 9)
  • Integration of sustained observations in the marine environment (Theme 10)

In the original programme proposal there was a theme on health and human impacts (Theme 7). The elements of this Theme have subsequently been included in Themes 3 and 9.

When is the programme active?

The programme started in April 2007 with funding for 5 years.

Brief summary of the programme fieldwork/data

Programme fieldwork and data collection are to be achieved through:

  • physical, biological and chemical parameters sampling throughout the North and South Atlantic during collaborative research cruises aboard NERC's research vessels RRS Discovery, RRS James Cook and RRS James Clark Ross;
  • the Continuous Plankton Recorder being deployed by SAHFOS in the North Atlantic and North Pacific on 'ships of opportunity';
  • physical parameters measured and relayed in near real-time by fixed moorings and ARGO floats;
  • coastal and shelf sea observatory data (Liverpool Bay Coastal Observatory (LBCO) and Western Channel Observatory (WCO)) using the RV Prince Madog and RV Quest.

The data is to be fed into models for validation and future projections. Greater detail can be found in the Theme documents.


Data Activity or Cruise Information

Cruise

Cruise Name D321 (D321A)
Departure Date 2007-07-24
Arrival Date 2007-08-23
Principal Scientist(s)John T Allen (National Oceanography Centre, Southampton)
Ship RRS Discovery

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
Q value below limit of quantification