The following 3 Search Criteria are mutually exclusive;
you can only Search on one of them: Source, NGDC Number or Survey Identifier.
You can choose to INCLUDE (the default) or EXCLUDE these criteria
in your Search.
The Source of Data Search Criteria allows you to choose sources (institutions, agencies, countries) to Search for. The listbox contains both Source Id (first 2 characters of the NGDC Number) and the Name of the source. You can select multiple sources by holding down the Control key while clicking on them with the mouse. For Windows only, this dialog also allows a word search of the Project and Platform fields of MGD77/HYD93 Headers. Words can be any combination of letters, including parts of words, and case will be ignored. Up to 3 words for each field can be entered, a "hit" to be determined by BOOLEAN OR. i.e. if any of 3 words entered were found in the field, the result would be a "hit". Contributing Source, Project Word Search, and Platform Word Search are 3 separate Search Criteria. This means that GEODAS Search will use BOOLEAN AND to determine whether indivdual surveys match the Search Criteria. i.e. If you chose InstX, and selected WordA for Project and WordB for Platform, the survey would match the Search Criteria only if it was an InstX survey and it contained WordA in the Project Field and WordB in the Platform Field..
The Select by NGDC Number criteria allows you to Search for specific
NGDC Numbers as found in the Search Summary listings.
You also have the option of typing
in the first 2 characters or the first 4 characters in order to
mix and match NGDC Numbers, Sources and Platform/Projects. The
codes for Sources (2 characters) and Platform/Projects (4 characters)
can be found as follows:
Codes for Marine Trackline Geophysical data in file trkdas.cod
Codes for NOS Hydrographic Surveys data in file hydnos.cod
Codes for Aeromagnetic data in file arodas.cod
Enter multiple identifiers by using the tab key or mouse to move the cursor
to the next entry block.