 |
|||
|
Page Title:
Table 9. Format and content for DCW library Data Quality Table (DQT)-cont. |
|
||
| ||||||||||
|
|  MIL-D-89009
TABLE 9.
Format and content for DCW library Data Quality Table
(DQT) - Continued.
DCW\
19911207000000.00000\
19580401000000.00000\
19890101000000.00000\
100 percent of attribute codes were reviewed against the source
manuscripts. No formal effort was undertaken to develop a quantitative
accuracy statement.\
100 percent of attribute codes were reviewed against the source
manuscripts. No formal effort was undertaken to develop a qualitative
accuracy statement.\
Operational Navigational Charts (ONC)\
NA
+/- 6700 feet: This figure represents overall library accuracy. Chart-
specific accuracies are available as area feature attributes in the DCW
data quality coverage. Detailed horizontal accuracy figures were
developed by comparing the positions of well-defined points in the
roads, railroads, utility lines, and drainage coverages against sources
of higher accuracy, measuring the offsets, and expressing differences as
a Circular Map Accuracy figure at a 90% confidence interval. This
figure was independently verified by adding known production errors to
source chart accuracies in a root sum square calculation. The primary
accuracy analysis was performed on one chart only in the prototyping
phase of the project.\
FEET\
+/- 2000 feet: This figure represents overall library accuracy.
Chart-specific accuracies are available as area feature attributes in
the DCW data quality coverage. Vertical accuracy figures were
developed by comparing elevation contour locations on 1:24,000 scale
maps to elevation values at the same location within the digital
database. Some manual interpolation was necessary to complete this
test. The analysis results are expressed as linear error at a 90%
confidence interval.\
FEET\
UNKNOWN\
N/A\
UNKNOWN\
N/A\
Additional descriptions of data lineage are available in the narrative
table associated with this data quality table (called lineage.doc).
f. Names placement coverage. The GAZETTE directory
consists of a names placement point feature table, which
contains information about the named features in the
names placement coverage, and the names placement entity
node primitive table, which contains the point location
in the coverage.
g. Library reference coverage. The LIBREF directory
contains a generalized line map over the extent of the
library and is spatially registered to the tile
reference coverage.
21
|
|
Privacy Statement - Press Release - Copyright Information. - Contact Us |
Click
here for thousands of PDF manuals