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Metadata Report for BODC Series Reference Number 932153

Metadata Summary

Data Description

Data Category Bathymetry
Instrument Type
Simrad EK-60 echosounder  Fish-finder echosounders
Trimble NT300D Global Positioning System receiver  NAVSTAR Global Positioning System receivers
Chernikeeff Aquaprobe Mk5 electromagnetic speed log  current meters
Instrument Mounting research vessel
Originating Country United Kingdom
Originator Mr Phil Knight
Originating Organization Proudman Oceanographic Laboratory (now National Oceanography Centre, Liverpool)
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) Coastal Observatory
Oceans 2025
Oceans 2025 Theme 10
Oceans 2025 Theme 10 SO11

Data Identifiers

Originator's Identifier PD07_08_PRODQXF_NAV
BODC Series Reference 932153

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2008-03-10 23:46
End Time (yyyy-mm-dd hh:mm) 2008-03-15 14:28
Nominal Cycle Interval 60.0 seconds

Spatial Co-ordinates

Southernmost Latitude 53.35433 N ( 53° 21.3' N )
Northernmost Latitude 54.07467 N ( 54° 4.5' N )
Westernmost Longitude 3.92567 W ( 3° 55.5' W )
Easternmost Longitude 3.01200 W ( 3° 0.7' W )
Positional Uncertainty 0.0 to 0.01 n.miles
Minimum Sensor or Sampling Depth -
Maximum Sensor or Sampling Depth -
Minimum Sensor or Sampling Height -
Maximum Sensor or Sampling Height -
Sea Floor Depth -
Sea Floor Depth Source -
Sensor or Sampling Distribution -
Sensor or Sampling Depth Datum -
Sea Floor Depth Datum -


BODC CODERankUnitsTitle
AADYAA011DaysDate (time from 00:00 01/01/1760 to 00:00 UT on day)
AAFDZZ011DaysTime (time between 00:00 UT and timestamp)
ALATGP011DegreesLatitude north (WGS84) by unspecified GPS system
ALONGP011DegreesLongitude east (WGS84) by unspecified GPS system
APDAZZ011Degrees TrueDirection of motion (over ground) of measurement platform {course made good}
APEWGP011Centimetres per secondEastward velocity (over ground) of measurement platform by unspecified GPS system
APNSGP011Centimetres per secondNorthward velocity (over ground) of measurement platform by unspecified GPS system
APSADG011Metres per secondSpeed (over ground) of measurement platform by Trimble DGPS
APSAWW011Metres per secondSpeed (through water) of measurement platform by electromagnetic log
HEADCM011DegreesOrientation (horizontal relative to true north) of measurement device {heading}
MBANUA011MetresSea-floor depth (below instantaneous sea level) {bathymetric depth} in the water body by echo sounder (SV=1500m/s)

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

Simrad EK60 Echosounder

The Simrad EK60 echosounder is a split-beam echosounder primarily designed for fisheries research. One or more acoustic transducers are mounted in the vessel's hull, allowing continuous monitoring of the water column along the ship's track. Seven transducer frequencies are available, ranging from 18kHz to 710 kHz. The EK60 also features a 150 dB instantaneous dynamic range and an adjustable ping rate up to 20 pings per second.

A portable version, known as the EY60, is also available.


Operational range 0 to 15000 m
Operating frequencies 18, 38, 70, 120, 200, 330 and 710 kHz
Ping rate Max 20 ping s-1 (adjustable)
Dynamic range 150 dB (instantaneous)
Receiver noise 4 dB
Operating temperature 0 to 55°C

Further details can be found in the manufacturer's brochure.

Chernikeeff Aquaprobe Mk5 Electromagnetic Speed Log

The Aquaprobe Mk5 EM Speed Log operates on the principle that a conductor (such as water) passing through an electromagnetic field will create a voltage whose magnitude increases as the speed of the conductor increases. The EM log includes one or two hull-mounted transducers, which generate an electromagnetic field and measure the voltage created by the flow of water through that field, thereby deducing the speed of the vessel through the water.

The EM log has the options of single or twin transducers, single or dual axis speed measurements and gate-valved (retractable) hull fitting or fixed transducers. The microprocessor calibration control ensures a high accuracy through the entire speed range.


Speed Range ± 40 knots or ± 80 knots
Total distance range 0 to 99999.99 nm
System accuracy
Speed < 10 knots ± 0.02 knots
Speed > 10 knots ± 0.2%
Distance 0.02% of speed
Calibrated accuracy
Speed < 10 knots ± 0.1 knots
Speed > 10 knots ± 1%
Distance 0.02% of speed

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

Trimble NT300D Geographical Positioning System (GPS)

The NT300D is a 12-channel GPS receiver with a built in dual-channel radiobeacon receiver. It can transmit positional information with an accuracy of <1 m up to five times per second with a maximum latency of 0.2 seconds. The radiobeacon receiver allows for intelligent and seamless switching between radio beacons, which improves performance and availability. The unit also accepts externally received corrections and allows the user to prioritise between those corrections and the corrections received by the internal beacon receiver. Positioning is based on carrier-phase filtered L1 (carrier frequency) pseudoranges over 183 user-selected datums.


Operating temperature 0 to 55°C
GPS receiver
Update rate 5 Hz with a latency < 200 ms
Differential speed accuracy 0.2 km h-1
Differential position accuracy

< 1 m RMS

at least 5 satellites

PDOP < 4

Time to first fix < 30 s (typical)
Beacon receiver
Frequency range 283.5 to 325 kHz
Channel spacing 500 Hz
MSK modulation 50, 100 and 200 bits s-1
Dynamic range 100 dB
Acquisition time 2 to 5 s (typical)

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

PD07_08 Navigation instrument details

Instrument type Make and model Serial Number Manufacturer's details available?
GPS Trimble NT300D - Yes
Heading compass Plath Gyro Compass - -
Bathymetric echo sounder Simrad EK-60 Scientific Echo sounder EK-60 General Purpose Transceiver with a 120 kHz Split Beam transceiver module (1KW) 38kHz Split Beam transceiver (2KW) 29431 30138 Yes
Electromagnetic speed log Chernikeeff Aquaprobe MK5 Naval EM log - Yes

Prince Madog Cruise PD07_08 Navigation Series

Navigation Processing Notes

Prince Madog Cruise PD07_08 Sea Surface Hydrography, Meteorology and Navigation Series

Data acquisition

Surface hydrographic (ship's intake 3 m below surface), meteorology measurements and supplementary navigation data, including ship heading and bathymetric depth were time stamped and logged to a central logging system. The data underwent conversion from raw counts into engineering units and were submitted as daily text files to BODC, at 60 second resolution, for further processing.

There are two gaps in the data record, caused by the central logging system being switched off while the RV Prince Madog was docked or at anchor. These gaps are: (i) from 14:55 11 March 2008 to 04:50 13 March 2008, when the RV Prince Madog was moored in Vittoria Dock, Birkenhead due to bad weather and (ii) from 20:28 14 March 2008 to 05:41 15 March 2008 when the RV Prince Madog was anchored overnight at Coastal Observatory Site 21.

BODC underway data processing procedures

All underway sea surface hydrography, meteorology and ship's navigation data were merged into a common QXF file. Navigation was checked for improbable speeds and gaps and any additional data calibrations were applied as appropriate. The QXF file then underwent a further step. This involved using Matlab transfer 378 to split the underway QXF file into three separate QXF files. One contained data for sea surface hydrography, one for meteorological data and the final QXF file held the navigation data.

Each data channel was visually inspected on a graphics workstation and any spikes or periods of dubious data were flagged as suspect. The capabilities of the workstation screening software allows all possible comparative screening checks between channels (e.g. to ensure corrected wind data have not been influenced by changes in ship's heading). The system also has the facility of simultaneously displaying the data and the ship's position on a map to enable data screening to take oceanographic climatology into account.

Project Information

Proudman Oceanographic Laboratory Coastal Observatory

The Coastal Observatory was established by Proudman Oceanographic Laboratory as a coastal zone real time observing and monitoring system. The main objective is to understand a coastal sea's response both to natural forcing and to the consequences of human activity. Near real-time measurements will be integrated with coupled models into a pre-operational coastal prediction system whose results will be displayed on the World Wide Web.

The Observatory is expected to grow and evolve as resources and technology allow, all the while building up long time series. A site selection pilot study was carried out in September 2001 and the Observatory became operational in August 2002.

The site is located in Liverpool Bay and is subject to typical coastal sea processes, with strong tides, occasional large storm surges and waves, freshwater input, stable and unstable stratification, high suspended sediment concentration and biogeochemical interaction. Measurements and monitoring will focus on the impacts of storms, variations in river discharge (especially the Mersey), seasonality and blooms in Liverpool Bay.

A variety of methods will be used to obtain measurements, including:

  1. Moored instruments for in situ time series of currents, temperature and salinity profiles, and surface waves and meteorology. It is hoped that turbidity and chlorophyll measurements will be made at another site as the Observatory progresses;
  2. The Cefas Smartbuoy for surface properties such as nutrients and chlorophyll, starting late 2002;
  3. R.V. Prince Madog to carry out spatial surveys and service moorings;
  4. Instrumented ferries for near surface temperature, salinity, turbidity, chlorophyll and nutrients. The first route will be Liverpool to Douglas, Isle of Man, starting late 2002;
  5. Drifters for surface currents and properties such as temperature and salinity, starting in 2004;
  6. Tide gauges, with sensors for meteorology, waves, temperature and salinity, where appropriate;
  7. Meteorological data from Bidston Observatory and Hilbre Island, HF radar and tide gauge sites;
  8. Shore-based HF radar measuring waves and surface currents out to a range of 50 km, starting in 2003;
  9. Satellite data, with infrared for sea surface temperature and visible for chlorophyll and suspended sediment.

The partners currently involved with the project are listed below:

A summary of Coastal Observatory cruises to date on R.V. Prince Madog is given in the table below:

Year No. of cruises Work summary
2001 1 Site selection and pilot study. 95 CTD casts.
2002 4 POL moorings deployed and serviced
Cefas Waverider and SmartBuoy deployed and serviced
103 CTD casts
2003 10 POL moorings serviced
Cefas Waverider and SmartBuoy serviced
341 CTD/LISST casts
2004 9 POL moorings serviced
Cefas Waverider and SmartBuoy serviced
347 CTD/LISST casts
2005 9 POL moorings serviced
Cefas Waverider and SmartBuoy serviced
268 CTD/LISST casts
2006 11 POL moorings serviced
Cefas Waverider and SmartBuoy serviced
508 CTD/LISST casts
2007 9 POL moorings serviced
Cefas Waverider and SmartBuoy serviced
471 CTD/LISST casts
2008 9 POL moorings serviced
Cefas Waverider and SmartBuoy serviced
260 CTD/LISST casts
2009 7 POL moorings serviced
Cefas Waverider and SmartBuoy serviced
213 CTD/LISST casts
2010 8 POL moorings serviced
Cefas Waverider and SmartBuoy serviced
268 CTD/LISST casts
2011 6 POL moorings serviced
Cefas Waverider and SmartBuoy serviced
307 CTD/LISST casts to date, ongoing

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:

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:

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:

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

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:

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

Oceans 2025 Theme 10

Oceans 2025 is a strategic marine science programme, bringing marine researchers together to increase people's knowledge of the marine environment so that they are better able to protect it for future generations.

Theme 10: Integration of Sustained Observations in the Marine Environment spans all marine domains from the sea-shore to the global ocean, providing data and knowledge on a wide range of ecosystem properties and processes (from ocean circulation to biodiversity) that are critical to understanding Earth system behaviour and identifying change. They have been developed not merely to provide long-term data sets, but to capture extreme or episodic events, and play a key role in the initialisation and validation of models. Many of these SOs will be integrated into the newly developing UK Marine Monitoring Strategy - evolving from the Defra reports Safeguarding our Seas (2002) and Charting Progress (2005), thus contributing to the underpinning knowledge for national marine stewardship. They will also contribute to the UK GOOS Strategic Plan (IACMST, 2006) and the Global Marine Assessment.

Weblink: http://www.oceans2025.org/

Oceans 2025 Theme 10, Sustained Observation Activity 11: Liverpool Bay and Irish Sea Coastal Observatory

Sustained, systematic observations of the ocean and continental shelf seas at appropriate time and space scales allied to numerical models are key to understanding and prediction. In shelf seas these observations address issues as fundamental as 'what is the capacity of shelf seas to absorb change?' encompassing the impacts of climate change, biological productivity and diversity, sustainable management, pollution and public health, safety at sea and extreme events. Advancing understanding of coastal processes to use and manage these resources better is challenging; important controlling processes occur over a broad range of spatial and temporal scales which cannot be simultaneously studied solely with satellite or ship-based platforms.

Considerable effort has been spent by the Proudman Oceangraphic Laboratory (POL) in the years 2001 - 2006 in setting up an integrated observational and now-cast modelling system in Liverpool Bay (see Figure), with the recent POL review stating the observatory was seen as a leader in its field and a unique 'selling' point of the laboratory. Cost benefit analysis (IACMST, 2004) shows that benefits really start to accrue after 10 years. In 2007 - 2012 exploitation of (i) the time series being acquired, (ii) the model-data synthesis and (iii) the increasingly available quantities of real-time data (e.g. river flows) can be carried out through Sustained Observation Activity (SO) 11, to provide an integrated assessment and short term forecasts of the coastal ocean state.

BODC image

Overall Aims and Purpose of SO 11

Measurement and Modelling Activities

More detailed information on this Work Package is available at pages 32 - 35 of the official Oceans 2025 Theme 10 document: Oceans 2025 Theme 10

Weblink: http://www.oceans2025.org/


IACMST., 2004. The Economics of Sustained Marine Measurements. IACMST Information Document, N0.11, Southampton: IACMST, 96 pp

Data Activity or Cruise Information


Cruise Name PD07/08
Departure Date 2008-03-10
Arrival Date 2008-03-15
Principal Scientist(s)Phil J Knight (Proudman Oceanographic Laboratory)
Ship RV Prince Madog

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