Using a Geographic Coordinate System
A geographic coordinate system (GCS) can be applied to structural-scale and earth-scale data.
- Structure-scale data is
used when designing buildings, stadiums, industrial plants, and other
structures to assign the appropriate coordinate system for the structure.
Design teams elect to place the origin at the front left corner of the building
at ground level, with the positive X axis aligned with the front of the
building, positive Y aligned with the side of the building and Z representing
elevation above ground level. All data entry and readout is relative to that
coordinate system. The geographic location and orientation of the structure are
not considered in selecting the coordinate system.
For multiple structures where each is drawn in a coordinate system without Geo-Coordination, you can create a GCS that matches the existing coordinate system using placemarks.
- Earth-scale data is used when designing larger scale infrastructure, mapping, and surveying to select the appropriate projected geographic coordinate system that supplies a Cartesian coordinate system appropriate for the design location. When the same GCS is used for multiple design files, they can be easily referenced to each other. Referencing data that uses a different GCS, however, requires special calculations.
The Geographic Coordinate System dialog is used to select a geographic coordinate system (GCS) to apply to design data.