Datum

lastmod 2019-11-25created 2014-07-097 edits

Datum = Ellipsoid + Coordinate (system).

In GIS, the ellipsoid is the Earth Ellipsoid, and the coordinate system is the Geographic Coordinate Systems.

MapView coordinate conversion

Source code for MapView coordinate conversion (lat/long↔TM, lat/long↔KATEC, KATEC↔TM).

• http://www.androidpub.com/1318647 ¹
• http://javaexpert.tistory.com/142 ²

Worldwide, latitude/longitude (the WGS84 ellipsoid) is used. But in Korea, for its accuracy and convenience, the TM coordinate system (which has since changed again) is used at the national level.
The KATEC coordinate system is slightly less accurate than TM but more convenient, so it is used as the coordinate system of navigation companies and some portal map services.

Sample code

Datum_converter_for_java.zip

Source code that converts between the Google Maps lat/long coordinate system (wgs84), Daum/Kongnamul Map (modified tm), and Naver Map (katech or tm128) coordinate systems.

Types of datums

• WGS84: World Geodetic System 1984.
• Tokyo Datum: Tokyo Datum (Bessel Ellipsoid). (日本測地系)

See also

• GIS
• Geographic Coordinate Systems: Notes on geographic coordinate systems.
• Earth Ellipsoid: Notes on the Earth ellipsoid.

Favorite site

• THE REPUBLIC OF KOREA (Grids & Datums) PDF
• EPSG 4326 vs EPSG 3857 (projections, datums, coordinate systems, and more!)
• EPSG codes and proj4 parameters for major Korean coordinate systems

References