map accuracy

map accuracy

(1) (Data West Research Agency definition: see GIS glossary.) The closeness of results of observations, computations, or estimates of graphic map features to their true value or position. Relative accuracy is a measure of the accuracy of individual features on a map when compared to other features on the same map. Absolute accuracy is a measure of the location of features on a map compared to their true position on the face of the Earth. Mapping accuracy standards generally are stated as acceptable error and the proportion of measured features that must meet the criteria. In the case of some plotting and display devices, accuracy refers to tolerance in the display of graphic features relative to the original coordinate file.

(2) (Data West Research Agency definition: see GIS glossary.) The level of allowable error of maps, as applied by National Map Accuracy Standards, is determined by comparing the positions of well-defined points whose locations or elevations are shown on the map with corresponding positions as determined by surveys of a higher accuracy. The accuracy of any map is equal to the error inherent in it as due to the curvature and changing elevations contained in each map from which the map was made, added to or corrected by the map preparation techniques used in joining the individual maps.
Mentioned in ?
References in periodicals archive ?
The new ASPRS standards were created by the ASPRS Map Accuracy Standards Working Group, a joint panel under the Photogrammetric Applications Division, Primary Data Acquisition Division and Lidar Division, which was established to assess and update ASPRS map accuracy standards to reflect existing technologies.
Map quality was quantified by two measures: map accuracy and accuracy of each participant's interpretation of the overall geologic structure.
We selected NAVTEQ for its superior map accuracy and extensive global coverage.
Finally, results from each method were reviewed separately and then the amount of each method and map accuracy and were evaluated.
0 provides software-based map accuracy and content enhancement solutions.
This report from the National Research Council of the National Academies assesses current FEMA flood map accuracy and notes that despite recent conversions to digital media, only 21% of all maps meet or exceed data quality thresholds.
Geological Survey digital ortho quarter quadrangles have a map accuracy of 10 meters.
GPS will help document map accuracy, and global coordinates will record each ball marker, on spreadsheet records and AutoCAD drawings of the site.
Accuracy will vary due to variables in GPS units, map accuracy, and plotting accuracy.
FEMA's Digital Flood Insurance Rate Maps (DFIRMS) are built to national map accuracy standards.
Input from Global GPS Community Helps Create New Geometry in Multiple European Countries, Enhances Maps of Asia Pacific Region, Sets New Standard for Map Accuracy
It has been 50 years since any mapping has been accomplished and what we have does not meet the National Map Accuracy Standards (NMAS), according to DOT officials.