claudius ptolemy invented the system of latitudes and longitudes, measuring latitude from the equator in 2nd century a.d.
claudius ptolemy invented the system of latitudes and longitudes, measuring latitude from the equator in 2nd century a.d.
who invented the system of latitudes and longitudes, measuring latitude from the equator in 2nd century a.d?
claudius ptolemy
longitudes, which were difficult to determine at the time, are given in terms of degrees east from the fortunate islands (considered by claudius ptolemy as the westernmost known land) which waldseemüller locates at the canary islands. the longitudes of eastern asian places are too great. latitudes, which were easy to determine, are also quite far off. for example, "serraleona" (sierra leone, true latitude about 9°n) is placed south of the equator, and the cape of good hope (true latitude 35°s) is placed at 50°s.
waldseemüller map
decimal degrees









































decimal degrees (dd) express latitude and longitude geographic coordinates as decimal fractions and are used in many geographic information systems (gis), web mapping applications such as openstreetmap, and gps devices. decimal degrees are an alternative to using degrees, minutes, and seconds (dms). as with latitude and longitude, the values are bounded by ±90° and ±180° respectively.









































positive latitudes are north of the equator, negative latitudes are south of the equator. positive longitudes are east of prime meridian, negative longitudes are west of the prime meridian. latitude and longitude are usually expressed in that sequence, latitude before longitude.









































section::::precision.
decimal degrees