Metadata Report for BODC Series Reference Number 1717477
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
Quality report - iSTAR Moorings
It is clear from data from pressure sensors (and other sensors measuring the orientation of instruments on the mooring) that the iSTAR moorings were occasionally displaced in the water column. Given the location of the mooring it is likely that this disruption was caused by ice bergs knocking in to the mooring array. This was particularly noticeable in the data from moorings iSTAR6 (where the array became ~ 60m deeper on 05 January 2013), iSTAR9 (where the array became ~ 10 m deeper between 14 and 17 November 2013) and PIG_S (where the array became ~ 50 m deeper on the 20 July 2014 and then ~50 m deeper again on 30 July 2015).
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
Nortek Aquadopp Open Water Current Meter
This instrument provides 3D acoustic doppler current measurements along with standard measurements of temperature, pressure, tilt and direction. It can be used in real time measurement situations or can log to an internal recorder powered by internal batteries. It can also be configured to measure surface wave height, period and direction concurrently. It has the unique feature of being run in 'diagnostic' mode when set to collect data at 1 Hz frequency in user specified intervals. This allows studies of mooring motion and the performance of other current meters to be conducted. It can be set in various configurations with titanium housings for deployment at greater depths.
Standard Measured Parameters
- 3D current velocity (East/North/Up, X/Y/Z or Beam 1/2/3)
- Acoustic signal strength (Beam 1/2/3)
- Compass
- Tilt
- Temperature
- Pressure
- Battery voltage
- Status code
- Error code
Surface wave monitoring
The standard Aquadopp is suitable for measuring surface wave height, period, and direction, which are calculated using the PUV method whereby spectra are estimated based on a combination of the pressure signal recorded by the instrument (P) and two horizontal components of the wave orbital velocity (U and V). More specifically, the pressure signal is used to provide an estimate of the wave frequency spectrum. The energy in this spectrum is then used to estimate wave height and period. The measurements of the wave orbital velocities are used to provide an estimate of the wave direction. Since these estimates are based on the distribution of wave energy and are not direct measurements of the free surface, they should be considered inferred estimates.
Both the dynamic pressure and the orbital velocities are driven by surface waves. The signals that are associated with these properties are complicated by the fact that they attenuate (that is the signals are weaker) with depth. The exact behaviour of the attenuation is determined by the water depth and the wavelength being observed. The greater the water depth the greater the attenuation; likewise, the shorter the wavelength (or higher the frequency of the wave) the greater the attenuation for a given water depth. This means that the estimation of wave parameters is limited by both water depth and wave frequency.
Specifications
Water Velocity Measurement | |
---|---|
Range | ± 5 m/s (standard 300 m version) ± 3 m/s (3000 m and 6000 m versions - higher ranges available on request) |
Accuracy | 1% of measured value ± 0.5 cm/s |
Max. sampling rate | 1 Hz, 4 Hz also available on request (standard version) |
Internal sampling rate | 23 Hz |
Measurement Area | |
Measurement cell size | 0.75 m |
Measurement cell position | 0.35 - 5.0 m |
Default position | 0.35 - 1.8 m |
Doppler uncertainty (noise) | |
Typical | 0.5 - 1.0 cm/s |
At 1 Hz sampling rate | 1.5 cm/s |
Echo Intensity | |
Acoustic frequency | 2 MHz |
Resolution | 0.45 dB |
Dynamic range | 90 dB |
Sensors | |
Temperature | Thermistor embedded in head |
Range | -4°C to 40°C |
Accuracy/resolution | 0.1°C / 0.01°C |
Time response | 10 min |
Compass | Magnetometer |
Accuracy/Resolution | 2° / 0.1° for tilt < 20° |
Tilt | Liquid level |
Maximum tilt | 30° |
Up or down | Automatic detect |
Pressure | Piezoresistive |
Range | 0 - 300 m (standard), 0 - 3000 m or 0 - 6000 m |
Accuracy/resolution | 0.5% |
Analogue Inputs | |
No. of channels | 2 |
Voltage supply | 12 V |
Voltage input | 16 bit A/D |
Materials | |
Standard version | Delrin with titanium screws |
3000 m version | Delrin with titanium screws |
6000 m version | Titanium with Delrin transducer head |
Environmental | |
Operating temperature | -4°C to 40°C |
Dimensions | |
Cylinder | 568 mm x 75 mm (standard) 619 mm x 84 mm (3000 m version) 625 mm x 84 mm (6000 m version) |
Weight in air | 3.5 kg (standard) 3.6 kg (3000 m version) 7.6 kg (6000 m version) |
Weight in water | Neutral (standard) 1.2 kg (3000 m version) 4.8 kg (6000 m version) |
Further details can be found in the manufacturer's specification sheets for the Aquadopp, Aquadopp 3000 and Aquadopp 6000.
BODC Processing - iSTAR Moored Nortek Aquadopps
Data were received by BODC in Matlab files, with one file containing all data from an iSTAR mooring array. The data were reformatted to QXF (a NetCDF file format) by in house software. A separate QXF file was created for data from each instrument. Metadata were also extracted from the originator's file and used to populate the BODC database.
The following tables shows how the variables within the files were mapped to appropriate BODC parameter codes:
Originator's parameter name | Originator's units | Description | BODC Parameter Code | BODC Units | Comments |
---|---|---|---|---|---|
temp | Degrees Celsius | Temperature of the water body | TEMPPR01 | Degrees Celsius | |
press | dbar | Pressure (measured variable) exerted by the water body by semi-fixed in-situ pressure sensor and corrected to read zero at sea level | PREXPR01 | dbar | Depth data were also supplied by the originator but have not been ingested at BODC |
speed | cm/ s | Current speed (Eulerian) in the water body | LCSAZZ01 | cm/ s | |
dir | Degrees | Current direction in the water body | LCDAZZ01 | Degrees | |
u | cm/s | Eastward current velocity in the water body | LCEWZZ01 | cm/s | |
v | cm/s | Northward current velocity in the water body | LCNSZZ01 | cm/s | |
w | cm/s | Upward current velocity in the water body | LRZAZZZZ | cm/s | |
pitch | Degrees | Orientation (pitch) of measurement platform by triaxial fluxgate compass | PTCHFG01 | Degrees | |
roll | Degrees | Orientation (roll angle) of measurement platform by triaxial fluxgate compass | ROLLFG01 | Degrees | |
heading | Degrees | Orientation (horizontal relative to true north) of measurement platform {heading} by compass | HEADCM01 | Degrees | |
amp1 | Raw count | Signal return amplitude from the water body by in-situ current meter beam 1 | ISCMBMA1 | dimensionless | |
amp2 | Raw count | Signal return amplitude from the water body by in-situ current meter beam 2 | ISCMBMA2 | dimensionless | |
amp3 | Raw count | Signal return amplitude from the water body by in-situ current meter beam 3 | ISCMBMA3 | dimensionless | |
battery | Volts | Voltage (battery output) by in-situ current meter | BTVOLTCM | Volts |
Following transfer to QXF, the data were quality controlled using BODC's in-house visualisation software.
Originator's processing - iSTAR Moored Nortek Aquadopps
Data processing
The originator calibrated data from the moorings with data from CTD casts taken at deployment and recovery. Where appropriate offsets were applied (these are documented in the table below.
The magnetic variation calculated from the International Geomagnetic Reference Field (IGRF) at each mooring position on 01 January 2013 was recorded. The following variables had magnetic variation corrections applied by the originator:
- current direction
- northward component of current
- eastward component of current
Magnetic variation corrections weren't applied to heading
Mooring | Serial number | Temperature offset applied (degrees Celsius) | Pressure offset applied (dbar) | Magnetic variation recorded |
---|---|---|---|---|
istar1 | aqd_9392 | 0.0380 | -5.2000 | 50.2416 |
istar4 | aqd_9396 | 0.1170 | -4.2000 | 50.9101 |
istar5 | aqd_9368 | 0.0760 | -5.8000 | 50.7405 |
istar5 | aqd_9375 | 0.0570 | -14.2000 | 50.7405 |
istar5 | aqd_9386 | 0.1090 | -4.4000 | 50.7405 |
istar6 | aqd_9382 | 0.0260 | -5.9000 | 49.5150 |
istar8 | aqd_9391 | 0.0170 | -5.7000 | 48.0830 |
istar9 | aqd_9398 | 0.0380 | -3.5000 | 48.3715 |
trough_w | aqd_9368 | 0.0760 | -5.8000 | 50.1867 |
trough_w | aqd_9386 | 0.1090 | -4.4000 | 50.1867 |
trough_e | aqd_9375 | 0.0570 | -14.2000 | 43.9542 |
trough_e | aqd_9396 | 0.1170 | -4.2000 | 43.9542 |
pig_n | aqd_9391 | 0.0170 | -5.7000 | 47.9776 |
pig_s | aqd_9398 | 0.0380 | -3.5000 | 48.2791 |
Project Information
No Project Information held for the Series
Data Activity or Cruise Information
Data Activity
Start Date (yyyy-mm-dd) | 2012-03-06 |
End Date (yyyy-mm-dd) | 2014-03-02 |
Organization Undertaking Activity | British Antarctic Survey |
Country of Organization | United Kingdom |
Originator's Data Activity Identifier | iSTAR1 |
Platform Category | subsurface mooring |
iSTAR1 Mooring
iSTAR1 is a mooring array deployed for the iSTAR programme. The mooring was deployed from RV Araon in March 2012 and recovered from RRS James Clark Ross cruise JR20140126 in March 2014.
Deployment date (UTC) | 2012-03-06 16:00 |
---|---|
Recovery date (UTC) | 2014-03-02 13:09 |
Latitude (+ve North) | -71.5622 |
Longitude (+ve East) | -113.0460 |
Nominal water depth (m) | 605 |
Instrument setup
Instrument | Serial number | Nominal depth of instrument (m) | Comments |
---|---|---|---|
Aquatec Aqualogger 520PT Temperature/ Pressure Recorder | 1313 | 352 | |
Aquatec Aqualogger 520T Temperature Recorder | 360 | 381 | |
Aquatec Aqualogger 520T Temperature Recorder | 1218 | 411 | |
Aquatec Aqualogger 520T Temperature Recorder | 361 | 441 | |
Aquatec Aqualogger 520T Temperature Recorder | 1219 | 471 | |
75 kHz LR RDI ADCP | 15519 | 498 | |
SeaBird SBE-37 Microcat | 8530 | 501 | |
Aquatec Aqualogger 520T Temperature Recorder | 1220 | 527 | |
Aquatec Aqualogger 520T Temperature Recorder | 1221 | 557 | The originator has raised concerns about calibration of this instrument and an offset has been applied to the temperature data based on calibration CTD casts at deployment and recovery. |
Nortek Aquadopp | 9392 | 587 | |
SeaBird SBE-37 Microcat | 8531 | 588 |
Related Data Activity activities are detailed in Appendix 1
Fixed Station Information
Fixed Station Information
Station Name | iSTAR1 (trough_W) |
Category | Coastal location |
Latitude | 71° 33.43' S |
Longitude | 113° 2.76' W |
Water depth below MSL | 605.0 m |
iSTAR1 (trough_W)
Fixed station Area | Latitude, degrees (positive North) | Longitude, degrees (positive East) |
---|---|---|
North-West corner | -71.5572 | -113.046 |
South-East corner | -71.5622 | -113.032 |
Water depth = 605 m
Sampling history
Activity | Latitude | Longitude | Deployment date | Recovery date | Instruments | Deployment ship/ cruise | Recovery ship/ cruise | Comments |
---|---|---|---|---|---|---|---|---|
iSTAR1 Mooring | -71.5622 | -113.0460 | 2012-03-06 | 2014-03-02 | one Aquatec Aqualogger (temperature and pressure) six Aquatec Aqualoggers (temperature only) two SeaBird SBE-37 Microcats one 75 kHz RDI ADCP one Nortec Aqaudopp | RV Araon | RRS James Clark Ross JR20140126 | |
CTD Cast 97 | -71.5572 | -113.0323 | 2014-03-02 | N/A | SeaBird SBE 911plus CTD C-Star transmissometer Aquatracka Fluorometer SeaBird SBE-43 Oxygen sensor PAR sensor Altimeter PA200 | RRS James Clark Ross JR20140126 | N/A | |
CTD bottle samples | -71.5572 | -113.0323 | 2014-03-02 | N/A | Salinity | RRS James Clark Ross JR20140126 | N/A | |
LADCP Cast 97 | -71.5572 | -113.0323 | 2014-03-02 | N/A | RDI 300 kHz Workhorse LADCP attached to CTD frame | RRS James Clark Ross JR20140126 | N/A | |
trough_W mooring | -71.5621 | -113.0437 | 2014-03-02 | 2016-02-07 | one Aquatec Aqualogger (temperature and pressure) three Aquatec Aqualoggers (temperature only) two SeaBird SBE-37 Microcats one 75 kHz RDI ADCP one Nortec Aqaudopp | RRS James Clark Ross JR20140126 | RV Araon ANA06B |
Related Fixed Station activities are detailed in Appendix 2
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 |
Appendix 1: iSTAR1
Related series for this Data Activity are presented in the table below. Further information can be found by following the appropriate links.
If you are interested in these series, please be aware we offer a multiple file download service. Should your credentials be insufficient for automatic download, the service also offers a referral to our Enquiries Officer who may be able to negotiate access.
Series Identifier | Data Category | Start date/time | Start position | Cruise |
---|---|---|---|---|
1717059 | Hydrography time series at depth | 2012-03-06 16:04:59 | 71.5622 S, 113.04598 W | Not applicable |
1717060 | Hydrography time series at depth | 2012-03-06 16:05:00 | 71.5622 S, 113.04598 W | Not applicable |
1717115 | Hydrography time series at depth | 2012-03-06 16:09:45 | 71.5622 S, 113.04598 W | Not applicable |
1717103 | Hydrography time series at depth | 2012-03-06 16:09:57 | 71.5622 S, 113.04598 W | Not applicable |
1717373 | Hydrography time series at depth | 2012-03-06 16:10:03 | 71.5622 S, 113.04598 W | Not applicable |
1717139 | Hydrography time series at depth | 2012-03-06 16:10:13 | 71.5622 S, 113.04598 W | Not applicable |
1717084 | Hydrography time series at depth | 2012-03-06 16:10:14 | 71.5622 S, 113.04598 W | Not applicable |
1717127 | Hydrography time series at depth | 2012-03-06 16:10:23 | 71.5622 S, 113.04598 W | Not applicable |
1717096 | Hydrography time series at depth | 2012-03-06 16:14:43 | 71.5622 S, 113.04598 W | Not applicable |
1748544 | Currents -subsurface Eulerian | 2012-03-06 17:00:00 | 71.5622 S, 113.04598 W | Not applicable |
1748556 | Currents -subsurface Eulerian | 2013-01-01 00:02:23 | 71.5622 S, 113.04598 W | Not applicable |
1748568 | Currents -subsurface Eulerian | 2014-01-01 00:05:18 | 71.5622 S, 113.04598 W | Not applicable |
Appendix 2: iSTAR1 (trough_W)
Related series for this Fixed Station are presented in the table below. Further information can be found by following the appropriate links.
If you are interested in these series, please be aware we offer a multiple file download service. Should your credentials be insufficient for automatic download, the service also offers a referral to our Enquiries Officer who may be able to negotiate access.
Series Identifier | Data Category | Start date/time | Start position | Cruise |
---|---|---|---|---|
1717059 | Hydrography time series at depth | 2012-03-06 16:04:59 | 71.5622 S, 113.04598 W | Not applicable |
1717060 | Hydrography time series at depth | 2012-03-06 16:05:00 | 71.5622 S, 113.04598 W | Not applicable |
1717115 | Hydrography time series at depth | 2012-03-06 16:09:45 | 71.5622 S, 113.04598 W | Not applicable |
1717103 | Hydrography time series at depth | 2012-03-06 16:09:57 | 71.5622 S, 113.04598 W | Not applicable |
1717373 | Hydrography time series at depth | 2012-03-06 16:10:03 | 71.5622 S, 113.04598 W | Not applicable |
1717139 | Hydrography time series at depth | 2012-03-06 16:10:13 | 71.5622 S, 113.04598 W | Not applicable |
1717084 | Hydrography time series at depth | 2012-03-06 16:10:14 | 71.5622 S, 113.04598 W | Not applicable |
1717127 | Hydrography time series at depth | 2012-03-06 16:10:23 | 71.5622 S, 113.04598 W | Not applicable |
1717096 | Hydrography time series at depth | 2012-03-06 16:14:43 | 71.5622 S, 113.04598 W | Not applicable |
1748544 | Currents -subsurface Eulerian | 2012-03-06 17:00:00 | 71.5622 S, 113.04598 W | Not applicable |
1748556 | Currents -subsurface Eulerian | 2013-01-01 00:02:23 | 71.5622 S, 113.04598 W | Not applicable |
1748568 | Currents -subsurface Eulerian | 2014-01-01 00:05:18 | 71.5622 S, 113.04598 W | Not applicable |
1748894 | Hydrography time series at depth | 2014-03-02 16:49:59 | 71.56212 S, 113.04637 W | RRS James Clark Ross JR20140126 (JR294, JR295) |
1748697 | Currents -subsurface Eulerian | 2014-03-02 16:50:00 | 71.56212 S, 113.04637 W | RRS James Clark Ross JR20140126 (JR294, JR295) |
1748716 | Currents -subsurface Eulerian | 2014-03-02 16:50:00 | 71.56212 S, 113.04637 W | RRS James Clark Ross JR20140126 (JR294, JR295) |
1748870 | Hydrography time series at depth | 2014-03-02 16:50:00 | 71.56212 S, 113.04637 W | RRS James Clark Ross JR20140126 (JR294, JR295) |
1748882 | Hydrography time series at depth | 2014-03-02 16:50:00 | 71.56212 S, 113.04637 W | RRS James Clark Ross JR20140126 (JR294, JR295) |
1748950 | Hydrography time series at depth | 2014-03-02 16:50:00 | 71.56212 S, 113.04637 W | RRS James Clark Ross JR20140126 (JR294, JR295) |
1763909 | Hydrography time series at depth | 2014-03-02 16:50:01 | 71.56212 S, 113.04637 W | RRS James Clark Ross JR20140126 (JR294, JR295) |
1763910 | Hydrography time series at depth | 2014-03-02 16:50:01 | 71.56212 S, 113.04637 W | RRS James Clark Ross JR20140126 (JR294, JR295) |