The following 3 Search Criteria are mutually exclusive;
you can only Search on one of them: Source/Project, NGDC Number or Survey Identifier.
You can choose to INCLUDE (the default) or EXCLUDE these criteria
in your Search.
The Source/Project of Data Search Criteria allows you to choose sources (institutions, agencies, countries) and projects to Search for. The listbox contains both Source/Project Number and the appropriate title for the source/project. You can select multiple sources by holding down the Control key while clicking on them with the mouse.
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.