Key Terms

datum

ellipsoid

geoid

geodesy

NAD27

NAD83

WGS84

datum transformation

geographic coordinate system (GCS)

latitude

Equator

longitude

Prime Meridian

degrees, minutes, and seconds (DMS)

decimal degrees (DD)

great circle distance

time zones

International Date Line

map projection

Universal Transverse Mercator (UTM)

UTM zone

easting

northing

false northing

false easting

United States National Grid (USNG)

State Plane Coordinate System (SPCS)

SPCS zone