Metadata Report for BODC Series Reference Number 1837234
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
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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 | |
---|---|
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 |
BODC Processing of RRS Discovery Vessel Mounted ADCP Data
The data arrived at BODC in 19 Pstar files containing data collected from the 150kHz vessel mounted ADCP during cruise D312. The data were reformatted to BODC's internal NetCDF format. The following table shows the mapping of variables within the Matlab files to appropriate BODC parameter codes:
Originator's variable | Units | BODC Parameter code | Units | Comments |
---|---|---|---|---|
time | seconds | - | - | Not transferred |
bindepth | metres | DBINAA01 | metres | - |
evelcal | cm/s | LREWAS01 | cm/s | Relative to ship's movement |
nvelcal | cm/s | LRNSAS01 | cm/s | Relative to ship's movement |
ve | cm/s | APEWGP01 | cm/s | - |
vn | cm/s | APNSGP01 | cm/s | - |
velvert | cm/s | LRZAAS01 | cm/s | - |
velerr | cm/s | LERRAS01 | cm/s | - |
absve | cm/s | LCEWAS01 | cm/s | - |
absvn | cm/s | LCNSAS01 | cm/s | - |
good3bm | % | - | - | Left as dummy channel - will not be transferred |
a-ghdg | deg | - | - | A derived parameter, therefore not transferred |
ampl | Db | ASAMAS01 | Db | - |
lat | deg | ALATGP01 | deg | - |
lon | deg | ALONGP01 | deg | - |
distrun | km | - | - | A derived parameter, therefore not transferred |
The data were then visualised using the in-house EDSERPLO software.
OCEANS 2025 cruise D312 150kHz Shipboard ADCP originator data processing
The following was taken from the D312 cruise report. The data were collected using a narrowband RDI 150 kHz Vessel-Mounted Acoustic Doppler Current Profiler (SN: 34). For more detailed information please refer to the cruise report.
Bottom tracking was used over the continental shelf after departing Reykjavik as well as on its return on to port the Scottish continental shelf.
The data were acquired using IBM Data Acquisition Software version 2.48 with profiler software 17.10.
ADCP setup
Variable | Setting |
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Number of Bins | 96 |
Bin size | 4m |
Blanking distance | 4m |
Transducer depth | 5.3m |
Processing mode | Single-ping mode: bottom-tracking and water-tracking |
Field Calibrations
Due to bad weather, a calibration of the 150 kHz VMADCP could not be achieved using bottom tracking data. Instead, the mean was taken from two previous calibrations obtained on cruises D306 and D309.
Using long, straight, steady speed sections of standard two minute ensemble profiles over reasonably constant bottom depth the following calibrations for mis-alignment angle, Ø, and necessary amplification (tilt), A, were derived by comparing GPS derived component vectors of the vessel speed and direction with processed VMADCP bottom track determined component vectors of the vessel speed and direction:
Ø (mis-alignment angle):
- mean = 0.6610
A (tilt):
- mean = 1.0000
Further information on calibration of the VMADCP can be found in the cruise report.
Project Information
Northern Seas Programme
The Northern Seas describes an area extending from the Irish and northern North Sea across the Norwegian Sea up to the marginal Arctic pack-ice zone, including territorial waters of the UK, Norway, Iceland, Denmark and Russia. These waters are an important marine environment playing a significant part in regulating world climate due to the area's role in thermocline circulation in addition to acting as a sink for man-made pollutants carried north by ocean currents. These environments are experiencing increasing pressures from both natural and human impacts and consequently the Northern Seas Programme was developed to help advance the understanding of how marine systems in Northern Seas respond to environmental and anthropogenic change.
Scientific Objectives
The central aim of the programme was to 'improve understanding of how the sensitivity of marine ecosystems to environmental perturbation, both natural and anthropogenic, varies along a latitudinal gradient'.
This aim was addressed through the following integrated themes:
Theme A: Understanding fjordic systems: insights for coastal and oceanic processes
Theme B: Ocean Margins: the interface between the coastal zone and oceanic realm
Theme C: Measuring and modelling change: sea sensors and bioinformatics
The Northern Seas Programme was active between 2001 and 2007. The fieldwork programme to address these objectives was conducted by staff from the Scottish Association for Marine Science (SAMS).
Data Activity or Cruise Information
Cruise
Cruise Name | D312 |
Departure Date | 2006-10-11 |
Arrival Date | 2006-10-31 |
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 |