World Geodetic System 1984 (WGS84 or EPSG:4326)
- 世界大地测量系统
- Earth’s center mass as the coordinate origin
- It comprises of a reference ellipsoid, a standard coordinate system, altitude data and a geoid.
Coordinate systems
- Geocentric: (X,YZ)
- Spherical: Latitude, Longitude, Height
- Cartesian
Universal Transverse Mercator (UTM)
- one of the most common map projections today
- 60 UTM zones on earth
Geometry vs Geography
- planar vs spherical