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|  MIL-D-89009
APPENDIX
40.3 Feature table narrative files. While the DQ coverage
describes problems varying spatially across the database, feature
table narrative files describe issues specific to entire feature
classes within coverages. All DCW coverage feature tables have
narrative files associated with them. These are readily
identifiable through their naming conventions, which include the
coverage name combined with the feature class to form the file
prefix, and a ".doc" suffix (e.g., the narrative file associated
with drainage lines is called "DNLINE.DOC"). Feature table
narrative files are divided into four sections: (1) general
information, (2) special automation techniques, (3) feature
coincidence, and (4) database design issues. The first section
contains general comments about a given feature type relating to
its fitness for use. The second section provides information on
any special processing techniques or tools that were used when
constructing the data. The third section, feature coincidence,
describes the positional relationships between feature types both
within the same coverage and with those contained in other
coverages. The fourth section, database design issues, relates
primarily to decision rules employed when translating hardcopy
features into digital ones.
40.4 Feature table attributes. The most detailed source of
DQ information within the DCW database is found on the primitive
attribute level. Most DCW coverages contain a "STAT" field in
their primitive feature tables that serves as a modifier to a
standard "TYPE" field. Many of the STAT fields include values for
expressing data reliability (e.g., "approximate alignment" in the
roads coverage), although most features do not have a specific
reliability code associated with them. The existence of "no data"
areas (e.g. hypsography information is absent or incomplete in
some areas) is defined primarily through TYPE fields.
40.5 Using DCW data quality information. Users of the DCW
will interact with the data quality information in a variety of
ways. The data quality tables, their lineage.doc files, and the
feature table narrative files are designed for interactive use
with VPFVIEW. Although they may be reviewed through the software,
their main purpose is to provide the serious database user with
in-depth information on database history and detailed database
characteristics. The data quality coverage is more useful to the
interactive user in that it provides a graphic framework
consistent with the other data types. A DCW user in VPFVIEW can
interactively display and query the data quality coverage to
better understand the characteristics of the database within any
defined region. Finally, the user can readily identify and
display explicitly stored unreliable data elements or "no data"
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