Metadata Report for BODC Series Reference Number 751984
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
Data Description |
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Parameters |
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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 |
| B | nominal value |
| Q | value below limit of quantification |
