I was googling coordinate related information all the day. Now I am confused with some concepts and terms. I hope some one can help me to make it clear.
Geographic coordinate system
Geographic coordinate is used to describe the location of the earth in a three-dimension which will base on the ellipsoid and a datum. And I always thought that the geographic coordinate are always the latitude and longitude. Am I wrong?
Projected coordinate system
It seems that the projected coordinate system will contains three points:
The projection itself. It means how the earth will be translate to a two-dimension surface. For example the
The geographic coordinate system which this pcs working for.
The Mathematics manner to translate the geographic coordinate to projection coordinate. BTW, is projection coordinate always a point inside the the Cartesian coordinate system? And is projection coordinate only fit for one kind of geographic coordinate system?
Coordinate reference system
Now I have no idea about what a coordinate reference system is. Is the Coordinate reference system has anything to do with the projection?
BTW,is the geodetic latitude is measured on the surface of the referenced ellipsoid?