Explanatory Notes Further details of BODCs activities within OMEX are given in a paper
"Data Management for the OMEX Project : A Case
Study" |
In order to keep track of all the diverse data being collected in OMEX, BODC maintains a data tracking spreadsheet with entries for each cruise as follows: ship name and country (of principal scientist), cruise identifier, name of principal scientist, start and end dates for the cruise, and a flag to indicate whether a cruise report has been received by BODC. Each data set collected on the cruise is accorded a single line entry comprising a count of the number of units of data in the data set (where known), a short data set descriptor and a flag (awaiting data/data received) to indicate whether the data set has been submitted to BODC. Source material for BODC's data tracking spreadsheet is normally compiled from cruise reports or, when these are not available, from Cruise Summary Reports or other material submitted to BODC. However, in some cases, the information is not made available to BODC until the data have actually been submitted!! Therefore, despite BODC's best endeavours, the data tracking information should not be regarded as being comprehensive. Where available, small-scale cruise track plots contained in the cruise reports or other documents are optically scanned when received at BODC and their images are made available through these WWW pages. WWW pages have been prepared from the data tracking spreadsheet and comprise a full list of the OMEX cruises, together with the information currently available to BODC on the data sets collected on each cruise and, where available, a cruise track chart image. The pages are updated as and when new information is received by BODC. |
The BODC data tracking spreadsheet serves as a first level data inventory for OMEX, and is the precursor to the building up of the 'data event' table where details on each data collecting event are logged. The 'data event' concept is central to BODC's database design for OMEX and covers everything collected on each cruise. Data events may be as simple as opening a tap to collect a sample of pumped surface sea water or more substantial activities such as a CTD cast, a vertical net haul, a horizontal trawl, a SeaSoar tow, a bottom core or a mooring. Each 'data event' is accorded a one line entry in BODC's main Oracle database and is described in terms of date/time, geographic position, gear code, water depth and various identifiers. In the first instance, the 'data event' information is compiled from cruise reports and other source material as available. At a later stage, when the data are received and being banked, this information is verified and edited as necessary - where earlier information is not made available, the 'data event' entries are compiled when the data are submitted. The 'data event' table serves two functions for OMEX - on the one hand it forms a second level data inventory/data tracking system for OMEX data while on the other, as and when the actual data are loaded, it serves as the top level entry point into the OMEX database. The WWW pages compiled from BODC's 'data event' table comprise a summary of 'data events' logged to date for OMEX together with a simplified listing of each of the 'data event' entries. Because of delays in the submission of cruise reports to BODC, the 'data event' table may be incomplete. The 'data event' WWW pages are updated daily to include any new information that becomes available to BODC. |
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Updated : 11 September 2003, Feedback :
© NERC
presented at
an EC workshop on data management