What is a common choice of coordinates?
latitude, longitude and elevation
Define a geographic coordinate system?
a coordinate system used in geography that enables every location on Earth to be specified by a set of numbers, letters or symbols.
and how are the coordinates chosen?
1 number is for vertical, 2-3 for horizontal
What is required to specify a location in a 2d map?
map projection
Who is credited for the invention of the coordinate system?
Eratosthenes
In what century?
3rd century BC
Who improved it later?
Hipparchus
by doing what?
determining latitude from stellar measurements
What did Marinus of Tyre do?
compiled an extensive gazetteer
where did Eratosthenes invent this system?
at the Library of Alexandria