% Galway Bay Cable Observatory Data Files % Adam Leadbetter % 2015-09-28
##General Directory Structure The data files are arranged in a directory structure by instrument type, specific instrument, and then year, month, day e.g.
- {InstrumentTypeA}
| - {InstrumentMakeModelSerialNumberA}
|- 2015
|- 10
|- 01
|- 02
- {InstrumentTypeB}
|- {InstrumentMakeModelSerialNumberB}
|-2015
|- 10
|- 01
|- 02
During the day, data files are streamed from the sensors to these directories. At the end of the day an archive file is created containing the full set of data produced during the day. For line oriented data, a single .txt file containing the concatenated results is created. For file oriented data, both a .zip and a .tar.gz compressed archive of the day's files is created in the folder. Once the daily archive has been produced, the individual files may be removed. After the end of a month, a .zip and a .tar.gz archive for the full month is also created for ease of data delivery.
An Idronaut Ocean-Seven 304 Conductivity-Temperature-Depth probe is installed on the observatory infrastructure. It measures the temperature and conductivity of the seawater (the conductivity is used to calculate an estimate of the salinity); the pressure exert by the seawater above (from which the depth of the sensor is estimated); and these parameters are also used to estimate the speed of sound within the sea.
The data files produced by the CTD are available here. The data files contain the following columns:
Date-time|InstrumentID| {Tab separated data columns}
- Date-time is a time stamp from a Global Positioning System receiver at the cable observatory shore station in the format YYYY-MM-DDThh:mm:ss.sss where:
- YYYY is the year
- MM is the month number within the year (e.g. 03 for March)
- DD is the day number within the month
- T delimits between the date and time
- hh is the hour within the day
- mm is the minute within the hour
- ss.sss is the second.milliseconds within the minute
- Z indicates the GPS timestamp is in Co-ordinated Universal Time (UTC)
- Instrument-ID is a unique identifier for the instrument based on its manufacturer, model number and serial number
- Seawater pressure in decibars
- Temperature of the seawater in degrees Celsius
- Electrical conductivity of the seawater in Siemens per metre
- Salinity of the seawater (salinity has no units)
- Sound velocity in seawater in metres per second
- Instrument time stamp in the format hh:mm:ss.ssM
###Fluorometer
A WetLabs ECO-FLNTU (serial number #3137) is installed on the observatory infrastructure. It measures the fluorescence of the seawater to give an estimate of the volume of chlorophyll present (indicative of the amount of phytoplankton in the seawater) and it measures turbidity, or the "cloudiness" of the seawater, caused by the presence of particles such as sediment from the seabed suspended in the water.
The data files produced by the fluorometer are available here. The data files contain the following columns:
Date-time|InstrumentID| {Tab separated data columns}
- Date-time is a time stamp from a Global Positioning System receiver at the cable observatory shore station in the format YYYY-MM-DDThh:mm:ss.sss where:
- YYYY is the year
- MM is the month number within the year (e.g. 03 for March)
- DD is the day number within the month
- T delimits between the date and time
- hh is the hour within the day
- mm is the minute within the hour
- ss.sss is the second.milliseconds within the minute
- Z indicates the GPS timestamp is in Co-ordinated Universal Time (UTC)
- Instrument-ID is a unique identifier for the instrument based on its manufacturer, model number and serial number
- Instrument clock date in the format MM/DD/YYYY
- Instrument clock time in the format hh:mm:ss
- Wavelength of light used to make fluorescence measurements in nanometres
- Chlorophyll fluorometer instrument output (counts) (no units)
- Wavelength of light used to make turbidity measurements in nanometres
- Optical scattering turbidity sensor instrument output (counts) (no units)
- Thermistor