Description of Spatial Data-Base Documentation

This report documents the spatial data base with a description for each coverage or data- table. Coverages have a figure showing its spatial extent accompanying its description. The format for the documentation is shown below.

COVERAGE OR DATA TABLE NAME (for example, BENCHMARK)

Description:               This field contains a brief description of the 
                           coverage or data table. 

Data type:                 For coverages, this field identifies the 
                           geographic features as POLYGON, LINE, or 
                           POINT. For data tables, the field contains DATA 
                           TABLE.

Source:	                   The references for the source data are cited in 
                           this field.

Source scale:	           For coverages, this field contains the scale of the 
                           source map.

Source projection:         For coverages, this field contains a description 
                           of the original source map projection, when 
                           known.

Method of entry:           This field describes procedures used to 
                           digitize the data. For example, data were 
                           either manually digitized, scanned, or
                           imported from (a) DXF files, (b) ARC/INFO 
                           interchange files, (c) latitude-longitude 
                           coordinates, or (d) text files. Specific 
                           information on the hardware and software used is 
                           included.

Quality control:           This field contains information on the specific
                           procedures used to verify the accuracy of digital 
                           conversions.

Projection of data:        This field contains the final map projection 
                           of the coverages in the data base. All 
                           coverages in the data base are stored in
                           the Universal Transverse Mercator (UTM) 
                           projection, zone 11. To maintain greater 
                           precision, 3.5 million meters were 
                           subtracted from the Y coordinates.

Final update:              This field contains the date that the coverage or 
                           data table was last updated. 

Description of variables:  This field contains the description of variables
                           in the attribute or data tables. Coverages may 
                           have more than one attribute table.


Variable                  Type             Length        Definition

NAME of the       Description of the    Length of the    A short description.
variable in        the variable type:     field.          of the variable.
the coverage       integer, character,
or data file.      binary, floating
                   decimal or date.

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