Metadata Report for BODC Series Reference Number 1814849
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
RRS James Cook cruise JC142 navigation quality control report
Bathymetry
The channel has been flagged throughout the cruise where noise in the channel moves away from the baseline bathymetry. Drop outs of zero values were converted to the absent data value. (BODC assessment)
There are breaks in the EM120 Swath data due to the acoustic instrumentation being isolated during Autosub and Moorings deployment and recovery. (Ship technician assessment).
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
Kongsberg EM120 Multibeam Echosounder
The EM120 is a low frequency (12 kHz) multibeam echosounder with full ocean depth capability designed for bathymetric surveys. It measures water depth by monitoring the travel time of an acoustic signal that is transmitted from the ship, reflected off the seabed and received back at the ship.
The main system units of the EM120 are transducer arrays (separate for reception and transmission), preamplifier unit, transceiver unit and operator unit. Sub-bottom profiling capability is an optional extra. For both transmit and receive arrays standard beamwidth is 1° or 2°, and 4° beamwidth is available for the receive array.
The system has 191 beams with pointing angles automatically adjusted according to achievable coverage or operator defined limits. The beam spacing is normally equidistant, corresponding to 1% of depth at 90° angular coverage, 2% at 120° and 3% at 140°. The transmit fan is split into several individual sectors, each of which is corrected independently for vessel roll, pitch and yaw, which places all soundings on a "best fit" to a line perpendicular to the survey line.
The EM120 supersedes the EM12 and was itself superseded by the EM122 in 2008.
Specifications
| Frequency | 12 kHz |
| Maximum ping rate | 5 Hz |
| Range sampling rate | 2 kHz |
| Swath coverage sector | up to 150° |
| Swath width | up to 5.5 x water depth |
| Depth resolution | 10 to 40 cm |
| Depth range | 20 to 11,000 m |
| Pulse length | 2, 5 and 15 ms |
| Number of beams | 191 |
| Beam width | 1° x 1° |
| Beam spacing (at angular coverage) | 1% of depth at 90° |
Further details can be found in the manufacturer's specification sheet.
RRS James Cook cruise JC142 navigation instrumentation
Instrumentation
| Manufacturer | Model | Function | Comments |
| Trimble/Applanix | POSMV | DGPS and attitude | Scientific primary source of position. |
| Kongsberg Maritime | Simrad EA600 | Single-beam echo sounder (port drop keel) | Corrected with constant sound velocity of 1500 ms-1 |
| Kongsberg Maritime | Simrad EM120 | Multi-beam echo sounder (shallow) | Corrected for local sound velocity using SVPs |
Trimble Applanix Position and Orientation Systems for Marine Vessels (POSMV)
The Position and Orientation Systems for Marine Vessels (POSMV) is a real time kinematic (RTK) and differential global positioning system (DGPS) receiver for marine navigation. It includes an inertial system that provides platform attitude information. The instrument provides accurate location, heading, velocity, attitude, heave, acceleration and angular rate measurements.
There are three models of Applanix POSMV, the POS MV 320, POS MV Elite and the POS MV WaveMaster. POS MV 320 and POS MV WaveMaster are designed for use with multibeam sonar systems, enabling adherence to IHO (International Hydrographic Survey) standards on sonar swath widths of greater than ± 75 degrees under all dynamic conditions. The POS MV Elite offers true heading accuracy without the need for dual GPS installation and has the highest degree of accuracy in motion measurement for marine applications.
Specifications
POS MV 320
| Componenet | DGPS | RTK | GPS Outage |
|---|---|---|---|
| Position | 0.5 - 2 m 1 | 0.02 - 0.10 m 1 | <2.5 m for 30 seconds outages, <6 m for 60 seconds outages |
| Roll and Pitch | 0.020° | 0.010° | 0.020° |
| True Heading | 0.020° with 2 m baseline 0.010° with 4 m baseline | - | Drift <1° per hour (negligible for outages <60 seconds) |
| Heave | 5 cm or 5% 2 | 5 cm or 5% 2 | 5 cm or 5% 2 |
POS MV WaveMaster
| Accuracy | DGPS | RTK | GPS Outage |
|---|---|---|---|
| Position | 0.5 - 2 m 1 | 0.02 - 0.10 m 1 | <3 m for 30 seconds outages, <10 m for 60 seconds outages |
| Roll and Pitch | 0.030° | 0.020° | 0.040° |
| True Heading | 0.030° with 2 m baseline | - | Drift <2° per hour |
| Heave | 5 cm or 5% 2 | 5 cm or 5% 2 | 5 cm or 5% 2 |
POS MV Elite
| Accuracy | DGPS | RTK | GPS Outage |
|---|---|---|---|
| Position | 0.5 - 2 m 1 | 0.02 - 0.10 m 1 | <1.5 m for 60 seconds outages DGPS, <0.5 m for 60 seconds outage RTK |
| Roll and Pitch | 0.005° | 0.005° | 0.005° |
| True Heading | 0.025° | 0.025° | Drift <0.1° per hour (negligible for outages <60 seconds) |
| Heave | 3.5 cm or 3.5% 2 | 3.5 cm or 3.5% 2 | 3.5 cm or 3.5% 2 |
1 One Sigma, depending on quality of differential corrections
2 Whichever is greater, for periods of 20 seconds or less
Further details can be found in the manufacturer's specification sheet.
RRS James Cook cruise JC142 navigation data processing procedures
Originator's Data Processing
The data were logged by the TECHSAS (TECHnical and Scientific sensors Acquisition System) system into daily NetCDF files. The TECHSAS system is used as the main data logging system on NMF-SS operated reserach vessels. The daily TECHSAS NetCDF navigation and bathymetry files provided to BODC were used for BODC processing. Data were additionally logged into the RVS Level-C format files which have been archived at BODC.
Bathymetry
The EA600 was used with a constant sound velocity of 1500 ms-1 throughout the water column to allow it to be corrected for sound velocity in post processing.
The EM120 was fed attitude and position data from the Seapath 300 system due to its superior real time heave. The beam angle was set to 70° during transits and 45° while in the work area. At all times the spacing was equidistant.
Files delivered to BODC
| Filename | Content description | Format | Interval | Start date/time (UTC) | End date/time (UTC) | Comments |
| *-*-position-Applanix_GPS_JC1.gps | Position (latitude and longitude) (from POSMV) | NetCDF | ~ 1 sec. | 29/10/2016 10:45:38 | 08/12/2016 09:22:59 | - |
| *-*-gyro-GYRO1_JC1.gyr | True heading (from POSMV Gyro) | NetCDF | ~ 1 sec. | 29/10/2016 10:45:38 | 08/12/2016 09:22:59 | Scientific source of heading from the ship's gyros |
| *-*-EA600-EA600_JC1.EA600 | Depths from central beam EA600 single-beam echosounder | NetCDF | ~15 seconds | 30/10/2016 09:59:25 | 07/12/2016 06:45:09 | |
| *-*-sb_depth-EM120_JC1.depth | Depths from the EM120 multi-beam echosounder | NetCDF | ~5 seconds | 29/10/2016 10:47:37 | 08/12/2016 09:22:59 |
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BODC Data Processing
Data were banked at BODC following standard banking procedures. Data were averaged to 60 second intervals.
The originator's variables were mapped to appropriate BODC parameter codes as follows:
*-*-position-Applanix_GPS_JC1.gps
| Originator's variable | Originator's units | Description | BODC Code | BODC Units | Unit conversion | Comments |
| measureTS | day since 1899-12-30T00:00:00 UTC | Measure timestamp | Not transferred | |||
| gndspeed | knot | Ground speed | Not transferred. | |||
| gndcourse | Degrees | Ground course | Not transferred. | |||
| alt | meters | Altitude | Not transferred. | |||
| lat | decimal degrees | Latitude north | ALATGP01 | decimal degrees | none | |
| prec | dimensionless | Precision | Not transferred | |||
| lon | decimal degrees | Longitude east | ALONGP01 | decimal degrees | none | |
| Heading | degrees | True heading | Not transferred | |||
| Mode | dimensionless | GPS mode | Not transferred | |||
| time | days since 1899-12-30 00:00:00 UTC | Acquisition time | Not transferred |
*-*-gyro-GYRO1_JC1.gyr
| Originator's variable | Originator's units | Description | BODC Code | BODC Units | Unit conversion | Comments |
| heading | Degrees true | True heading | HEADCM01 | degrees | none | |
| time | days since 1899-12-30 00:00:00 UTC | acquisition time | Not transferred. |
*-*-sb_depth-EM120_JC1.depth
| Originator's variable | Originator's units | Description | BODC Code | BODC Units | Unit conversion | Comments |
| freq | kHz | Frequency | Not transferred | |||
| snd | meters | sounding | MBANSWCB | meters | none | Multi-beam - Best quality bathymetry channel |
| time | days since 1899-12-30 00:00:00 UTC | acquisition time | Not transferred |
*-*-EA600-EA600_JC1.EA600
| Originator's variable | Originator's units | Description | BODC Code | BODC Units | Unit conversion | Comments |
| DepthF | fathom | Depth in fathoms | Not transferred | |||
| depthm | meters | Depth in meters | MBANZZ01 | meters | none | Single beam |
| depthft | feet | Depth in feet | Not transferred | |||
| time | days since 1899-12-30 00:00:00 UTC | acquisition time | Not transferred |
All the reformatted data were visualised using the in-house EDSERPLO software. Suspect data were marked by adding an appropriate quality control flag.
Position
A check was run on positional data to identify gaps and improbable values (through the calculation of speed). There were small gaps (<2 mins) in the positional data. During BODC processing, these gaps were linearly interpolated to remove them. Two spikes in the data were identified where the speed check failed (03/12/2016 00:00:00 and 02/11/2016 12:49:00). They were subsequently removed and the gaps interpolated.
Ship Velocities
Ship velocities were calculated from the main latitude and longitude channels using standard BODC procedures.
GEBCO
GEBCO bathymetry was added to the file using the main latitude and longitude channels.
Distance Run
Distance run was calculated from the main latitude and longitude channels, starting from the beginning of the file, using BODC standard procedures.
Bathymetry
Bathymetry data were screened independently as well as against GEBCO bathymetry measurements. Bathymetry data from the EM120 multi -beam echo-sounder were deemed to be the best quality. The EM120 multi-beam was run with a local sound velocity correction. The EA600 single-beam is run without a sound velocity correction and appeared more noisy.
Calibration
No field calibrations have been applied.
Project Information
MarineE-tech Research Programme
MarineE-tech is a four year (2016-2020) research programme, jointly funded by the Natural Environment Research Council (NERC), Security of Supply of Mineral Resources (SoS Minerals), Engineering and Physical Sciences Research Programme (EPSRC), and the Sao Paulo Research Foundation (FAPESP). The aim of the programme is to improve understanding of E-tech element concentration in seafloor mineral deposits, in particular Cobalt Crusts (ferromanganese-cobalt-rich deposits), which are considered the largest yet least explored source of E-tech elements globally. Research will focus on two key aspects: The formation of the deposits, and reducing the impacts resulting from their recovery.
Background
Minerals are essential for economic development, the functioning of society and maintaining our quality of life. Consumption of most raw materials has increased steadily since World War II, and demand is expected to continue to grow in response to the burgeoning global population and economic growth, especially in Brazil, Russia, India and China (BRIC) and other emerging economies. We are also using a greater variety of metals than ever before.
New technologies such as those required for modern communication and computing and to produce clean renewable, low-carbon energy require considerable quantities of many metals. In light of these trends there is increasing global concern over the long-term availability of secure and adequate supplies of the minerals and metals needed by society. Of particular concern are 'critical' raw materials (E-tech elements), so called because of their growing economic importance and essential contribution to emerging 'green' technologies, yet which have a high risk of supply shortage.
The primary focus of the programme is on the processes controlling the concentration of these E-tech deposits and their composition at a local scale (10s to 100s square km). This will involve data gathering by robotic vehicles across underwater mountains and small, deep-sea basins off the coast of North Africa and Brazil. By identifying the processes that result in the highest grade deposits, we aim to develop a predictive model for their occurrence worldwide. Also to be addressed is how to minimise the environmental impacts of mineral recovery.
Further details are available on the MarineE-tech website.
Participants
Nine different organisations are directly involved in research for MarineE-tech. These institutions are:
- National Oceanography Centre (NOC) - Project Chief Scientist: Dr Bramley Murton
- British Geological Survey (BGS)
- University of Bath
- University of Leicester
- HR Wallingford
- Marine Ecological Surveys Limited (MESL)
- University of Sao Paulo
- Secretariat of the Pacific Community (SPC)
- Soil Machine Dynamics Limited (SMD)
Research details
Overall, two Science Goals and five Work Packages have been funded and are described in brief below:
Science Goal 1: Assess the processes controlling the genesis of marine Fe-Mn deposits and their E-tech element composition
The objective of Work Packages 1, 2 and 3 are to characterise local-scale environmental variables and their influence on the formation and composition of Fe-Mn deposits and hence to ultimately develop predictive models for these deposits. This work addresses Science Goal 1 of the NERC Programme (E-tech element cycling) and forms the central component of our proposal. It is made possible by the opportunity to deploy robotic underwater vehicles and instruments that will enable the detailed studies required to make significant advances in the understanding of these systems and their E-tech element budgets.
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Work Package 1: Local-scale processes, seafloor morphology, sampling and primary data interpretation (UK lead: NOC).
-
Work Package 2: Physical and chemical characterisation of crusts, development of a litho-,bio- and chemo-stratigraphic framework (BGS lead).
-
Work Package 3: Work package 3: Assessment of the role of microbes in E-tech element concentration and cycling and implications for bioprocessing (NOC lead with USP).
Science Goal 2: Environmental Impacts
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Work Package 4: Assessing the environmental impacts of Fe-Mn oxide deposit exploitation and E-Tech element extraction on periphery ecosystems (Marine Ecological Surveys Ltd, SOPAC and HR Wallingford).
- Work Package 5: Low-carbon extraction of E-Tech elements from Fe-Mn deposits (University of Bath lead).
Fieldwork and data collection
The project has two dedicated cruises: A UK expedition (JC142) sailed during late 2016 to the Tropic Seamount, north-east Atlantic, on the RRS James Cook. A further cruise is scheduled for 2017 and 2018 by the University of Sao Paulo focusing on the Rio Grande Rise and Sao Paulo Ridge, south-west Atlantic Ocean.
Activities will involve the deployment of underwater robotic technology including the ISIS Remotely Operated Vehicle (ROV) to sample over 100 locations of Fe-Mn crusts. Also to be utilised is the Autosub6000 Autonomous Underwater Vehicle (AUV) to image the lateral extent and thickness of crusts across the seamounts. Plume studies will also be undertaken to assess their impacts on peripheral ecosystems.
Data Activity or Cruise Information
Cruise
| Cruise Name | JC142 (MarineE-tech) |
| Departure Date | 2016-10-29 |
| Arrival Date | 2016-12-08 |
| Principal Scientist(s) | Bramley J Murton (National Oceanography Centre, Southampton) |
| Ship | RRS James Cook |
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 |
