USGS 100k Quadrangle Layer Metadata

Citation:

Citation_Information:

Originator: California Gap Analysis

Publication_Date: 19980630

Title: 1:100,000 Quadrangle Boundaries of California

Geospatial_Data_Presentation_Form: map

Publication_Information:

Publication_Place: Santa Barbara, California

Publisher: Biogeography Lab, University of California, Santa Barbara

Online_Linkage: <http://www.biogeog.ucsb.edu/projects/gap/gap_data.html>

Description: Boundaries of the 100k quadrangles of California to be used for geographic reference.

Supplemental Information: n/a

Data Set Status: in use

West Bounding Coordinate: -124.5048
East Bounding Coordinate: -114.2648
North Bounding Coordinate: 41.9886
South Bounding Coordinate: 32.4234

Theme Keyword: Geographic grid

Browse Graphic File Name: usgs100k.gif
Browse Graphic File Description: 100k quadrangle boundaries of California.
Browse Graphic File Type: GIF

Use Restrictions: none
Access Limitations: none
Native Data Set Environment:

ARC/INFO software version 7.0.3 running on IBM RS6000 with AIX 3.2.5

Raster File Format: n/a
Raster File Sensor: n/a
Vector File Format: ARCE7 (ARC/INFO Export format, version 7)
Nonspatial File Format: n/a

Attribute Accuracy:

Quad names were assigned from the Index to topographic and other Map Coverage: California, published by USGS and therefore should contain the correct official names. However, since these names were entered by hand, it is possible that typographic or logical errors could have been made.

Attribute Accuracy Explanation: n/a

Logical Consistency Report: n/a

Completeness Report:

Quadrangles cover the entire state of California and all polygons have a name corresponding to the USGS quadrangle map series name.

Horizontal Positional Accuracy: n/a
Horizontal Positional Accuracy Explanation:

This coverage was created from a grid in latitude and longitude coordinates. At that stage it was perfectly accurate. Positional errors would only arise in the projection from geographic coordinates into Albers equal area. The DENSIFY 0.03125 option was given in the PROJECT file to provide reasonable curvature of grid lines with spacing of vertices at 0.03125 degrees.

Vertical Positional Accuracy: n/a
Vertical Positional Accuracy Explanation: n/a

Source Information: n/a
Source Date: n/a
Source Distance Resolution: 50 meters

Process Description:

A grid of 30 minutes of latitude and and 60 minutes of longitude was created with the GENERATE command that included all of California. The index of topographic maps was consulted for assigning the official USGS 100k map series quadrangle name. The coverage was then projected into the standard Albers projection with the DENSIFY 0.03125 option in the PROJECT file to provide reasonable curvature of grid lines with spacing of vertices at 0.03125 degrees.

Native Data Structure: spatial vector
Raster File Row (Line) Count: n/a
Raster File Column (Sample) Count: n/a
Raster File Vertical (Band) Count: n/a
Raster File Number of Bytes per Pixel: n/a

Geographic Coordinate Units: Degrees, minutes and decimal seconds
Map Projection Name: Albers Conical Equal Area
Map Projection Description:

Projection ALBERS

Units METERS

Spheroid CLARKE1866

Parameters:

1st standard parallel 34 0 0.000
2nd standard parallel 40 30 0.000
central meridian -120 0 0.00
latitude of projection's origin 0 0 0.000
false easting (meters) 0.00000
false northing (meters) -4000000.0000

Distance Resolution (meters): 50
Altitude Resolution (meters): n/a

Attribute Label:

QUADNAME USGS 100k quad name

Attribute Definition Source: USGS, National Mapping Program. Index to topographic and other map coverage: California. 38121-MI-99X.

Entity and Attribute Detail Citation: n/a

Distributor:

Dr. Frank Davis
Department of Geography
University of California
Santa Barbara, CA 93106-4060

phone: 805-893-3438
fax: 805-893-3146
e-mail: fd@geog.ucsb.edu
ftp address: ftp://ftp.biogeog.ucsb.edu/pub/org/biogeog/data/gap_analysis
URL: http://www.biogeog.ucsb.edu/projects/gap/gap_data.html

Distribution Liability:

The University of California assumes no responsibility for application of the data beyond their original intent.

Standard Order Process:

Data are available through anonymous ftp and the World Wide Web at the ftp address and URL address listed under Distributor.

File Decompression Technique:

ARC/INFO export file (ARCE7) with NONE compression option.

Transfer Size: 0.35 megabytes (uncompressed)

Metadata Date: 07/09/98
Metadata Standard Name: Metadata Standards for Gap Analysis
Metadata Standard Version: 09/05/94
Metadata Review Date: n/a
Metadata Contact:

Dr. David Stoms
phone: 805-893-7655
fax: 805-893-3146
e-mail: stoms@geog.ucsb.edu

Contact Person Primary: Dr. David Stoms
Contact Mail Address:

Department of Geography
University of California
Santa Barbara, CA 93106-4060

Contact Voice Telephone: (805) 893-7655
Contact Facsimile Telephone: (805) 893-3146
Contact Electronic Mail Address: stoms@geog.ucsb.edu