Surface underway 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 surface underway 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 surface underway 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.
Ideally, data should be provided as a time series of averages and should be merged with the navigation data. It is advisable that each cruise constitute a single file with one averaged value per parameter, per record. We recommend an averaging interval of one minute in shelf sea areas or two minutes in the open ocean. A record should consist of date, time, navigation; all observed parameters and the number of raw observations used in the average. All relevant corrections and calibrations (laboratory and field) should be applied to the data. Sample data collected for calibration purposes should also be provided.
If the navigation data has not been merged with the observed data, they may be submitted as a separate file. This should be linkable using date and time. The navigation position should be applicable to the middle of the averaging interval.
Metadata specific to surface underway data
Underway collection details
- Ship and cruise identifier.
- Project (if applicable).
- Date/time of the start/end of the sampling.
- Location of the all individual sensors (Water inlet and meteorological).
- Method of positional fixing (i.e. GPS, DGPS).
- Depth of the water intake.
- Flow volume per unit time, flow rate, size of water line.
- Time lag for water moving between sensors (if applicable).
- Any other pertinent information (i.e. shading of PAR sensor)
- Instrument description, reference number, manufacturer, model, principle of measurement, method of recording — provide a literature reference, web site reference or briefly describe. Include — accuracy, resolution and response range of individual sensors.
- Instrument modifications and their effect on the data.
Sample data — for calibration purposes
- Details of water sampling system (automatic — manufacturer, model, number serial number or manual).
- Water sampling method, volume and time interval.
- Details of analyses and the elapsed time between collection and analysis.
Corrections and calibrations
- Correction for time lag between sensors.
- Correction for ships movement — for wind speed and direction.
- Report on any other corrections made (i.e. correction for increase in water temperature due to flow through ships intake lines).
- Laboratory calibrations.
- In-situ calibrations (i.e. comparisons with lowered near surface CTD or water samples).
- Equations used for computed values (excluding simple averaging).
- Adjustments made due to variations in calibrations.
- Filtering, de-spiking or smoothing methods.
- Editing and quality control methods.
- Quality control report.