CTD data submission
BODC aims to ensure that all data incorporated into our database are adequately documented to allow long term viability and future access. Therefore, key data set information (metadata) are important for each data set we receive.
Our 'General guide to data submission' provides details of
- Data delivery mechanisms.
- Data file format and file naming.
- Parameter descriptions.
- General data set information (basic metadata)
- Where, when and how the data were collected.
- Who was responsible for data collection and how you refer to your data set.
- What has been done to the data.
- Watch points for other users (e.g. problems encountered and comments on data quality).
BODC undertake the processing of CTD data collected on cruises associated with projects for which we provide an agreed data management role. If you wish to submit data for one of these please contact the Data Manager for the project.
Information specific to CTD data for which we do not undertake processing are described below. Metadata may be supplied in any standard document format (i.e. Microsoft Word or text), included in file headers or by providing a literature reference. Please do not be discouraged from sending us data even if some of the information is unavailable. We fully understand that there are many reasons why the standards specified may not be completely achieved.
Instructions for other data types are also available.
Data may be supplied as one file per CTD station or all CTD stations from a cruise in one file. Down cast data (if available) should always be present. If water samples have been collected, the discrete up cast value (measured at the time of the water sample) should be provided.
Data should be checked for quality and pre-edited or flagged for erroneous values. All relevant calibrations, laboratory and field, should be applied to the data. Discrete water samples collected for the purposes of calibration may also be submitted to BODC.
It is recommended that data set header information be included within the data file. However, if this is not possible sufficient indexing must be provided to link the information to the data values. Copies of the original CTD log sheets may also be supplied with the data.
To ease ingestion, it would be helpful to include a standardised data definition statement within the file header or adopt a uniform file format for all CTD stations from one cruise. If homogeneity is not possible, please document the changes in the file format and supply with the data.
Metadata specific to CTD data
- Ship and cruise identifier.
- Project (if applicable).
- CTD station identifier.
- Date/time of the start of the measurement.
- Position and method of position fix (i.e. DGPS, GPS).
- Water column depth (specify method — i.e. sounding and methodology, chart).
- Water sample references — collected for calibration purposes.
- Instrument description, reference number, manufacturer and model — provide a literature reference, web site reference or briefly describe. Include — accuracy, resolution and response range of individual sensors.
Sample data — for calibration purposes
- A description of or reference to full laboratory methods and procedures.
- Details of any external sample analysis, including the laboratory name and accreditation level.
- A description of or reference to any internal or external quality assurance procedures.
- Laboratory calibration coefficients.
- Field calibration coefficients (i.e. water samples).
- Filtering, de-spiking or smoothing methods.
- Editing and quality control methods.
- Quality control report.