Metadata Report for BODC Series Reference Number 649905
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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Time Co-ordinates(UT) |
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Parameters |
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Problem Reports
No Problem Report Found in the Database
Data Access Policy
Open 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.
If the Information Provider does not provide a specific attribution statement, or if you are using Information from several Information Providers and multiple attributions are not practical in your product or application, you may consider using the following:
"Contains public sector information licensed under the Open Government Licence v1.0."
Narrative Documents
RD Instruments 150kHz Narrow Band Acoustic Doppler Current Profiler
Specifications
Water velocity measurements relative to the ADCP | |
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Accuracy (long term) | 0.5 % of measured velocity ± 0.5 cm/s |
Statistical uncertainty for one ping (cm/s) | Depth cell length of 4, 8, 16 m = 26, 13, 6.5 respectively (for horizontal velocities using the standard transducer) |
Ping rate (pings per second) | 2 (100 pings averaged in ADCP) |
Maximum profiling range (meters) | 290 |
Minimum range to start of first depth cell (meters) | 4 |
Number of depth cells | 8 to 128 |
Velocity range | ± 0.01 to 9.5 m/s (horizontal) |
Velocity resolution (cm/s) | 0.25 or 0.125 |
Velocity measurements relative to the bottom and measurement of bottom depth | |
Accuracy | 0.5% of measured velocity ± 0.5 cm/s |
Statistical uncertainty of one ping (percent of measured velocity) | 3.5 (for horizontal velocities using the standard transducer) |
Ping rate (pings per second) | 0.9 (100 pings averaged in ADCP) |
Depth range | 290 (the maximum depth range can be up to 1.5 times greater than specified) |
Bottom depth resolution (meters) | 4 |
Velocity range | ± 0.01 to 9.5 m/s (horizontal) |
Velocity resolution (cm/s) | 0.25 or 0.125 |
Measurement of echo intensity | |
Accuracy (with temperature correction) | Before calibration : ± 8 dB, After calibration: ± 3 dB |
Statistical uncertainty for one ping | Approximately ± 5 dB |
Ping rate (pings per second) | 2 (100 pings averaged in ADCP) |
Profiling range (meters less than for water velocity measurement) | 64 |
Number of depth cells | 8 to 128 |
Dynamic range | 80 dB |
Resolution | 0.45 dB typical (temperature/system dependent) |
Data communication | |
Interface | Modified RS-232/422 serial at baud rates of 300-19,200 |
Data format | Binary (8-bit) or ASCII (76-character) lines separated by a carriage return/line feed. |
Data storage capacity | 2 MB (standard); expandable to 40 MB in 1 and/or 2 MB increments |
Power requirements | |
ADCP electronics | Voltage range (VDC) 6-12; Standby current (amps) 0.0002; Operate current (amps) 0.24; Peak current (amps) 0.5 |
transmit and EPROM recorder | Voltage range (VDC) 20-40; Standby current (amps) 0.0001; Operate current (amps) 0.10; Peak current (amps) 2.0 |
CTD sensors | Voltage range (VDC) 12-20; Standby current (amps) 0.0001; Operate current (amps) 0.022; Peak current (amps) 0.05 |
Temperature sensor | |
Accuracy | ± 0.2°C |
Time constant | Approximately 2 minutes |
Range | -5° to 45°C |
Resolution | 0.012°C |
Environmental | |
Operating temperature | -5°C to 40°C |
Humidity | Must be non-condensing |
Depth capability | 35 meters (transducer only) |
Physical characteristics | |
Weight in air | 67.6 kg |
Weight in water | 25.0 |
Diameter | 45.9 cm |
Length | 141.4 cm |
RRS Discovery 262 150kHz VMADCP
Deployment and originator's processing
Two RDI Vessel-Mounted Acoustic Doppler Current Profilers (VM-ADCPs) were operated on Discovery 262; the 150kHz VM-ADCP and the 75 kHz Phased Array instrument (Ocean Surveyor) that had been fitted immediately prior to FISHES (Discovery 253, May-June 2001). The 150 kHz ADCP is mounted in the hull 1.75 m to port of the keel, 33 m aft of the bow at the waterline and at an approximate depth of 5 m. The 75 kHz ADCP is mounted in a second well in the hull, but 4.15 m forward and 2.5 m to starboard of the 150 kHz well. The following table describes the setup of the 150kHz ADCP.
Frequency dependent constant | 4.17e5 |
Power into water (W) | 183.15 |
Dimensionless noise factor | 8.95 |
Bin length (m) | 4 |
Blanking distance (m) | 4 |
BODC processing
A total of 36 files were submitted to BODC. The data were supplied in P* binary format. The following variables were transferred to BODC QXF format (a BODC-defined subset of NetCDF and BODC's format for 2 dimensionsal datacycle storage) using transfer process tr363. The only variables not transferred were the non-calibrated backscatter and the time channel (the latter being automatically calculated by the transfer program).
BODC Code | Description | Units | Originator's variable |
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ALATGP01 | Latitude | degrees | lat |
ALONGP01 | Longitude | degrees | lon |
AADYAA01 | Date (time from 00:00 01/01/1760 to 00:00 UT on day) | days | time |
AAFDZZ01 | Time (time between 00:00 UT and timestamp) | days | time |
DBINAA01 | Bin depth | metres | bindepth |
ASAMAS01 | Signal return amplitude | decibels | ampl |
LCEWAS01 | Eastward current velocity (Eulerian) | cm/s | absve |
LCNSAS01 | Northward current velocity (Eulerian) | cm/s | absvn |
LERRAS01 | Current velocity error | cm/s | velerr |
LRZAAS01 | Upward current velocity | cm/s | velvert |
PCGDAP01 | Percentage good return signal | % | good |
Screening and Data quality
The data have been visually screened for obvious problems using the BODC EDSERPLO software. No significant problems were detected apart for the Eastward and Northward current velocities for day file with ISHREF 649616 (originator's id: adp26204.abs) which mirror the ship's velocity. Examination of the originator's pstar file reveals that the platform velocities are always zero for this particular file resulting in the error for absolute current velocity. To avoid confusion, the absolute current velocities for this file have been deleted. Note that, for an unkown reason, the first 6 day files (ISHREFs 04400, 04500, 04600, 04700, 04800, 04900) only have 64 bins each, ranging from 18m to 522m, compared to 100 bins within 14m to 410m range for all the other files.
Project Information
Marine Productivity programme (MarProd)
The Marine Productivity programme (MarProd) was a Thematic Programme of the Natural Environment Research Council. It was funded for a period of five years starting in 2000. Its main goal was "to develop coupled modelling and observation systems for the pelagic ecosystem, with emphasis on physical factors affecting zooplankton dynamics" with the following specific objectives:
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To identify the dominant spatial and temporal scales of physical parameters and zooplankton population dynamics, by observation, modelling and retrospective analysis
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To parameterise the critical processes governing zooplankton dynamics by observations and experiments
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To construct and validate spatially explicit models of zooplankton and their food and predators, capable of resolving short term changes in population structure
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To provide data for model validation by developing and applying new interdisciplinary techniques to a wide spectrum of biological and physical parameters
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To develop a database and information system for historic and new data and models.
The programme was composed of two phases: Phase 1 projects (2000-2002) focused on the use of historical datasets and existing biological models, complemented by laboratory experiments and remote-sensing analyses to gain a better understanding of the dynamics of zooplankton populations in shelf seas. The main, field-based Phase 2 of the programme (2001-2005) focused on the open ocean. The fieldwork phase took place between November 2001 and December 2002 and consisted of four surveys in the northern North Atlantic in early winter 2001 and 2002, and in spring and summer 2002.
MarProd was a major UK contribution to the international Global Ocean Ecosystem Dynamics project (GLOBEC).
Data Activity or Cruise Information
Cruise
Cruise Name | D262 |
Departure Date | 2002-04-18 |
Arrival Date | 2002-05-26 |
Principal Scientist(s) | Kelvin Richards (University of Southampton School of Ocean and Earth Science) |
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 |
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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 |