Metadata Report for BODC Series Reference Number 1964896
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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Parameters |
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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
RD Instruments- Ocean Surveyor 75kHz Vessel mounted ADCP.
| Long-Range Mode | ||
|---|---|---|
| Vertical Resolution Cell Size3 | Max. Range (m)1 | Precision (cm/s)2 |
| 8m | 520 - 650 | 30 |
| 16m | 560 - 700 | 17 |
| High-Precision Mode | ||
| Vertical Resolution Cell Size3 | Max. Range (m)1 | Precision (cm/s)2 |
| 8m | 310 - 430 | 12 |
| 16m | 350 - 450 | 9 |
1 Ranges at 1 to 5 knots ship speed are typical and vary with situation.
2 Single-ping standard deviation.
3 User's choice of depth cell size is not limited to the typical values specified.
Profile Parameters
- Velocity long-term accuracy (typical): ±1.0%, ±0.5cm/s
- Velocity range: -5 to 9m/s
- # of depth cells: 1 - 128
- Max ping rate: 0.7
Bottom Track
Maximum altitude (precision <2cm/s): 950m
Echo Intensity Profile
Dynamic range: 80dB
Precision: ±1.5dB
Transducer and Hardware
Beam angle: 30°
Configuration: 4-beam phased array
Communications: RS-232 or RS-422 hex-ASCII or binary output at 1200 - 115,200 baud
Output power: 1000W
Standard Sensors
Temperature (mounted on transducer)
- Range: -5° to 45°C
- Precision: ±0.1°C
- Resolution: 0.03°
Environmental
Operating temperature: -5° to 40°C (-5° to 45°C)*
Storage temperature: -30° to 50°C (-30° to 60°C)*
*later instruments have greater range.
Web Page
Further details can be found on the manufacturer's website or in the specification sheet
BAS Long term and Monitoring Survey Cruise JR20150309 (JR272D, JR310) 75kHz Shipboard ADCP data processing
Originator's Processing
VmDas software (version 1.42) was used for data acquisition, archiving and display. The final processing of data was performed using a set of Matlab routines during the cruise.
The instrument was set up to run in narrowband mode for the entire JR310 cruise. It was configured to acquire data in beam coordinate system, profiling 50 bins with a 16 m bin length, 1 profiling ping per ensemble. Blanking distance at the surface was set to 8 m; the ADCP was set to ping as fast as possible (in VmDas). It was run independently from the SSU all the time, with bottom tracking off and maximum bottom search depth of 800 m for most of the stations. The misalignment angle and scaling factor were calculated during post-processing.
Post-processing
The original Matlab scripts for processing the SADCP data were obtained originally from IFM Kiel, adapted and modified by several people through the years. Detailed information on processing steps and indvidual scripts can be found on the cruise report for cruise JR20070226 (JR165, JR170, JR174).
References
Weston, K.; brandon, M.; 2007. RRS James Clark Ross Cruise JR20070226 (JR165, JR170, JR174) , 26 Feb - 16 April 2007 . JR174 Cruise Report. University of East Anglia, UK and Open University, UK, 9pp..
BODC Processing
The data were provided to BODC in one Matlab file and were then 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 | Originator's Units | BODC Parameter Code | BODC Units | Comment |
|---|---|---|---|---|
| nav.txy1(3,:) | degrees | ALATZZ01 | degrees | - |
| nav.txy1(2,:) | degrees | ALONZZ01 | degrees | - |
| vel(:,1,:) | m s-1 | LCEWAS01 | cm s-1 | Conversion *100 applied |
| vel(:,2,:) | m s-1 | LCNSAS01 | cm s-1 | Conversion *100 applied |
| vel(:,3,:) | m s-1 | LRZAAS01 | cm s-1 | Conversion *100 applied |
| dbins | metres | DBINAA01 | metres | - |
The reformatted data were visualised using the in-house EDSERPLO software. Suspect data were marked by adding an appropriate quality control flag.
A number of gaps in the data were identified during the cruise period. These instances were likely set to null by the originator and as they have no data were left as they are but flagged Null during transfer.
Project Information
BAS Long Term Monitoring and Survey
Introduction
The Long Term Monitoring and Survey project (LTMS) has been running since the British Antarctic Survey (BAS) was created. This project is one of the BAS core projects, with several groups of scientists collecting various types of data e.g biological, geological, atmospheric, among others.
Data collection is achievable through a wide scope of instruments and platforms, e.g. the Antarctic research stations, autonomous instrument platforms deployed on or from BAS research ships, BAS aircrafts, satellite remote sensing and others.
Scientific Objectives
This project was implemented in order to measure change and variability in the Earth system. Its long term duration allows for the monitoring of processes that could be missed in shorter term studies and experiments. The data collected is also used to check and improve the reliability of models used to stimulate and predict the behavior of the Earth system.
The main objectives are:
- Topographic survey
- Geosciences survey
- Biological survey and monitoring
- Atmospheric and oceanographic monitoring
Data Availability
The data sets obtained through this project are available to the academic community.
Data Activity or Cruise Information
Cruise
| Cruise Name | JR20150309 (JR272D, JR310) |
| Departure Date | 2015-03-09 |
| Arrival Date | 2015-04-14 |
| Principal Scientist(s) | Povl Abrahamsen (British Antarctic Survey) |
| Ship | RRS James Clark Ross |
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 |
