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Metadata Report for BODC Series Reference Number 788339


Metadata Summary

Data Description

Data Category Multiple data types -ship
Instrument Type
NameCategories
Global Positioning Satellite System  NAVSTAR Global Positioning System receivers
Simrad EA500 echosounder  single-beam echosounders
Instrument Mounting research vessel
Originating Country United Kingdom
Originator Prof Mike Meredith
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) Rapid Climate Change Programme
 

Data Identifiers

Originator's Identifier CD160_PRODQXF_NAV
BODC Series Reference 788339
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2004-08-04 19:56
End Time (yyyy-mm-dd hh:mm) 2004-08-24 10:58
Nominal Cycle Interval 120.0 seconds
 

Spatial Co-ordinates

Southernmost Latitude 42.19400 N ( 42° 11.6' N )
Northernmost Latitude 47.47590 N ( 47° 28.6' N )
Westernmost Longitude 63.61570 W ( 63° 36.9' W )
Easternmost Longitude 52.17050 W ( 52° 10.2' W )
Positional Uncertainty 0.05 to 0.1 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 -
 

Parameters

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 relative to WGS84 by unspecified GPS system
ALONGP011DegreesLongitude east relative to WGS84 by unspecified GPS system
APDAAS011Degrees TrueDirection of motion of measurement platform relative to ground surface {course made good} by Ashtech GPS
APEWGP011Centimetres per secondEastward velocity of measurement platform relative to ground surface by unspecified GPS system
APNSGP011Centimetres per secondNorthward velocity of measurement platform relative to ground surface by unspecified GPS system
DSRNCV011KilometresDistance travelled
HEADCM011DegreesOrientation (horizontal relative to true north) of measurement device {heading}
MBANCT011MetresSea-floor depth (below instantaneous sea level) {bathymetric depth} in the water body by echo sounder and correction using Carter's tables
PTCHEI011DegreesOrientation (pitch) of measurement platform by inclinometer
ROLLEI011DegreesOrientation (roll angle) of measurement platform by inclinometer

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

RAPID Cruise CD160 Underway Navigation - Data Quality Report

It should be noted that data logging was suspended between 13/08/2004 and 18/08/2004 whilst the ship was in port for engine repairs.


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

Kongsberg Simrad EA500 bathymetric echosounder

The EA500 is a bathymetric echosounder that can be used in water as deep as 10,000 m. It features triple frequency operation with a separate digitiser for each channel and high transmitted power with an instantaneous dynamic range of 160 dB. The instrument can operate with several pulses in the water simultaneously and has bottom tracking capabilities. A wide range of transducers (single beam, split beam or side-looking) is available and the ping rate is adjustable up to 10 pings per second. The split beam operation measures the athwartships inclination angle of the seabed.

This instrument was introduced in June 1989 and and replaced by the EA 600 in 2000.

Specifications

Operational range 1, 5, 10, 15, 25, 50, 100, 150, 250, 500, 750, 1000, 2500, 5000 and 10000 m
Phasing 0 to 10000 m in 1 m increments (manual or automatic)
Non saturated instantaneous input range -160 to 0 dB
Output power regulation 0 to 20 dB relative to full power
Noise figure 10 dB
Operating temperature 0 to 55°C
Ping rate max 10 pings per second (adjustable)

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

Global Positioning Satellite System

A location system of unspecified make or model that determines location on the Earth's surface using the Global Positioning Satellite Network. Angular co-ordinates are given relative to WGS84 CRS. Other parameters such as platform velocity may be derived from this.

RAPID Cruise CD160 Underway Navigation Instrument Details

Instrument Type Make and Model Serial Number Comments
GPS 4000 Trimble 4000DL GPD receiver - -
GPS ASH Ashtech ADU-2 4 antenna atitude GPS receiver - -
GPS G12 Ashtech/Furgo Seastar differential GPS receiver - Primarily used to feed differential corrections to the Trimble 4000DL receiver
Bathymetric Echo Sounder Simrad EA-500 10kHz echo sounder - -
Heading Compass GYRONMEA - -

RAPID Cruise CD160 Sea Surface Hydrography, Meteorology and Navigation

Cruise details

Dates 5 - 24 August 2004
Principal Scientific Officer Mike Meredith (POL)

A full copy of the Metadata report can be found here: CD160

Data Aquisition and Onboard Processing

Meterological data were collected with a Vaisala QLI50 sensor collector (s/n: R381006) and sent, along with TSG system measurements, to the ship's central logging system. ASCII files were generated for each 24 hour period of the cruise and loaded into Matlab for further processing. Large spikes in conductivity and temperature were removed, and surface salinity calculated from conductivity and housing temperature data. An additional routine was run to determine the true wind speed and direction, taking account of the ship's motion. The data were subsequently averaged (2 minute resolution) with latitude and longitude interpolated to the SurfMet timestamps. Finally, one file was produced, containing the averaged data for the whole cruise.

BODC underway data processing

All underway sea surface hydrography, meteorology and ship's navigation data were merged into a common QXF file using time (GMT) as the primary linking key. Navigation was checked for improbable speeds and gaps, wind speed and direction were corrected for ship's motion and heading 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.

RAPID Cruise CD160 Underway Navigation Series Processing

Navigation

  • Positional data

    Bestnav GPS data were merged onboard with the SurfMet files.

Project Information

Rapid Climate Change (RAPID) Programme

Rapid Climate Change (RAPID) is a £20 million, six-year (2001-2007) programme of the Natural Environment Research Council (NERC). The programme aims to improve our ability to quantify the probability and magnitude of future rapid change in climate, with a main (but not exclusive) focus on the role of the Atlantic Ocean's Thermohaline Circulation.

Scientific Objectives

  • To establish a pre-operational prototype system to continuously observe the strength and structure of the Atlantic Meridional Overturning Circulation (MOC).
  • To support long-term direct observations of water, heat, salt, and ice transports at critical locations in the northern North Atlantic, to quantify the atmospheric and other (e.g. river run-off, ice sheet discharge) forcing of these transports, and to perform process studies of ocean mixing at northern high latitudes.
  • To construct well-calibrated and time-resolved palaeo data records of past climate change, including error estimates, with a particular emphasis on the quantification of the timing and magnitude of rapid change at annual to centennial time-scales.
  • To develop and use high-resolution physical models to synthesise observational data.
  • To apply a hierarchy of modelling approaches to understand the processes that connect changes in ocean convection and its atmospheric forcing to the large-scale transports relevant to the modulation of climate.
  • To understand, using model experimentation and data (palaeo and present day), the atmosphere's response to large changes in Atlantic northward heat transport, in particular changes in storm tracks, storm frequency, storm strengths, and energy and moisture transports.
  • To use both instrumental and palaeo data for the quantitative testing of models' abilities to reproduce climate variability and rapid changes on annual to centennial time-scales. To explore the extent to which these data can provide direct information about the thermohaline circulation (THC) and other possible rapid changes in the climate system and their impact.
  • To quantify the probability and magnitude of potential future rapid climate change, and the uncertainties in these estimates.

Projects

Overall 38 projects have been funded by the RAPID programme. These include 4 which focus on Monitoring the Meridional Overturning Circulation (MOC), and 5 international projects jointly funded by the Netherlands Organisation for Scientific Research, the Research Council of Norway and NERC.

The RAPID effort to design a system to continuously monitor the strength and structure of the North Atlantic Meridional Overturning Circulation is being matched by comparative funding from the US National Science Foundation (NSF) for collaborative projects reviewed jointly with the NERC proposals. Three projects were funded by NSF.

A proportion of RAPID funding as been made available for Small and Medium Sized Enterprises (SMEs) as part of NERC's Small Business Research Initiative (SBRI). The SBRI aims to stimulate innovation in the economy by encouraging more high-tech small firms to start up or to develop new research capacities. As a result 4 projects have been funded.


Data Activity or Cruise Information

Cruise

Cruise Name CD160
Departure Date 2004-08-04
Arrival Date 2004-08-24
Principal Scientist(s)Mike Meredith (Proudman Oceanographic Laboratory)
Ship RRS Charles Darwin

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