Missouri Code of State Regulations
Title 20 - DEPARTMENT OF COMMERCE AND INSURANCE
Division 2030 - Missouri Board for Architects, Professional Engineers, Professional Land Surveyors, and Professional Landscape Architects
Chapter 20 - Mapping Survey Standards
Section 20 CSR 2030-20.010 - Definitions

(1) A map is a graphic representation of the physical features (natural, artificial, or both) of a part of the whole of the earth's surface, by means of signs and symbols or photographic imagery, at an established scale, on a specified projection, and with the means of orientation indicated. A map may be in various forms such as printed maps, subdivision of land in the form of plats, or in graphic presentations on a computer screen such as in a Geographic Information System (GIS) or in a Land Information System (LIS).

(2) Horizontal map accuracy is defined as the root mean square (rms) error in terms of the project's planimetric survey coordinates (X,Y) for checked points as determined at full (ground) scale of the map. The rms error is the cumulative result of all errors including those introduced by the processes of ground control surveys, map compilation, and final extraction of ground dimensions from the map.

(3) Vertical map accuracy is defined as the rms error in elevation in terms of the project's elevation datum for well-defined points only.

(4) The rms error is defined to be the square root of the average of the squared discrepancies. In this case, the discrepancies are the differences in coordinate or elevation values as derived from the map and as determined by an independent survey of higher accuracy (check survey). Well-defined points are those that are easily visible and recoverable on the ground, such as: monuments or markers, bench marks, property boundary monuments; intersections of roads, railroads, etc.; corners of large buildings or structures (or center points of small buildings); etc. In general what is well defined will also be determined by what is plottable on the scale of the map within one one-hundredth inch (1/100"). Thus while the intersection of two (2) road or property lines meeting at right angles would come within a sensible interpretation, identification of the intersection of such lines meeting at an acute angle would obviously not be practicable within one one-hundredth inch (1/100"). Similarly, features not identifiable upon the ground within close limits are not to be considered as test points within the limits quoted, even though their positions may be scaled closely upon the map. In this class would come timber lines, soil boundaries, etc.