Geographic Coordinate Systems
Geo-Coordination lets you specify or view the position of your design content on the earth’s surface. Two-or three-dimensional Cartesian coordinate system designs can be coordinated with other data for which the geographic location is known. Geo-Coordination does not apply to designs that represent manufactured components or assemblies with no fixed earth location.
Establishing the geographic location of the infrastructure provides substantial advantages. For infrastructure designs occupying a volume of less than a cubic kilometer, the curvature of the earth does not need to be considered. Most designers prefer to work in a local coordinate system that is convenient for their building or plant.
For larger-scale designs such as roadways, utility outside plant, and natural resource modeling, the conventional approach is to use a Cartesian approximation to the earth’s surface that gives acceptable results in the vicinity of the design contents. In the United States, most roadway designs use State Plane coordinate systems. Other countries and local governing bodies establish geographic coordinate systems appropriate for their locations. Some natural resource companies and military organization also develop geographic coordinate systems for their particular purposes. You can simply work in the Cartesian coordinate system without considering that it is actually a carefully chosen geographic coordinate system.