6.11 U.S. National Grid Support
The U.S. National Grid is a point coordinate representation using a single alphanumeric coordinate (for example, 18SUJ2348316806479498).
This approach contrasts with the use of numeric coordinates to represent the location of a point, as is done with Oracle Spatial and with EPSG. A good description of the U.S. National Grid is available at http://www.ngs.noaa.gov/TOOLS/usng.html.
To support the U.S. National Grid in Spatial, the SDO_GEOMETRY type cannot be used because it is based on numeric coordinates. Instead, a point in U.S. National Grid format is represented as a single string of type VARCHAR2. To allow conversion between the SDO_GEOMETRY format and the U.S. National grid format, the SDO_CS package (documented in SDO_CS Package (Coordinate System Transformation)) contains the following functions:
Parent topic: Coordinate Systems (Spatial Reference Systems)