COLLECTION METADATA FOR DRG 24K CA

Scope and purpose A digital raster graphic (DRG) is a scanned image of a U.S. Geological Survey (USGS) standard series topographic map, including all map collar information. This particular dataset is composed of scans of the most current edition (as of date of scanning) of 1:24,000-scale topographic maps of California; the sheets were scanned by the Teale Data Center. The image inside the map neatline is georeferenced to the surface of the Earth and fitted to the Universal Transverse Mercator projection. The horizontal positional accuracy and datum of the DRG matches the accuracy and datum of the source map. The map is scanned at a min resolution of 250 dots per inch.

Total item count 2,851 items as of March 20, 2002.

Item types

Thesaurus or authority list for item types The ADL Object Type Thesaurus. .

Type Count

geospatial works 2,851

maps 2,851

Type		Count
geospatial works		2,851
maps		2,851

Spatial (geographic) coverage

Overall spatial coverage

Temporal coverage

Overall temporal coverage

Item formats

Thesaurus or authority list for item formats The item formats are loosely based on RFC 2046, Multipurpose Internet Mail Extensions (MIME)..

Format Count

Online 2,851

Image 2,851

TIFF 2,851

Format		Count
Online		2,851
Image		2,851
TIFF		2,851

Schema Principally, MARC 21. A locally developed schema, MIL-B, is used for fields that would otherwise be subsumed under MARC 21 field 500 (general note).

Sample record ADL full metadata report for item DRG o33119h6 Digital Raster Graphic, of SANTA CRUZ ISLAND B, CA, in XML and HTML.

Geographic locations

Description Geographic locations and regions described by latitude/longitude coordinates.

Metadata mapping MARC 21 fields 034 d, e, f, g (coded cartographic mathematical data---coordinates) and 255 c (cartographic mathematical data---statement of coordinates)..

Notes Queries against this bucket are evaluated using a Plate Carre projection, i.e., by treating latitude and longitude as Cartesian coordinates. Thus, query regions may not include the North or South Poles. Additionally, non-rectangular query regions may not intersect the +/-180 meridian.

Dates

Description Dates and date ranges.

Metadata mapping MARC 21 fields 008/07-14 (publication date(s)), 045 (time period of content), 260 c (publication, distribution, etc. (imprint)---date of publication, distribution, etc.), and 260 g (publication, distribution, etc. (imprint)---date of manufacture)..

Types

Description Terms drawn from a collection-dependent controlled vocabulary identifying meaning or content.

Metadata mapping The ADL Catalog item types, which are in turn derived from MARC 21 field 655 a (index term---genre/form)..

Formats

Description Terms drawn from a collection-dependent controlled vocabulary identifying form or representation.

Metadata mapping The ADL Catalog item formats..

Assigned terms

Description Subject-related terms from controlled vocabularies. This bucket is a subset of the "Subject-related text" bucket.

Metadata mapping MARC 21 fields 650 (subject added entry---topical term) and 651 (subject added entry---geographic name), and other 6XX (subject access) fields..

Notes Non-alphanumeric characters are treated as word separators.

Subject-related text

Description Subject-related text, not necessarily from controlled vocabularies. This bucket is a superset of the "Assigned terms" bucket.

Metadata mapping MARC 21 fields 245 (title statement), 500 (general note), 520 (summary, etc.), and others.

Notes Non-alphanumeric characters are treated as word separators.