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Geographic Coordinates

Question asked by CADEngr2014 on May 31, 2019
Latest reply on Jun 3, 2019 by MKennedy-esristaff



I am using Arc Map 10.4.1.


I am at odds with the terminology of "Geographic" coordinate and inquire for a better understanding.  I have heard many interpretations of this term.  Such as: a datum is geographic if one is using lat-long coordinates.  Which I have always assumed belong to a "round" earth.  However, there are graticules associated with a flat map, that I believe, sometimes have lat-long, such as along the edges of a quad map.  When viewing graphics set to a coordinate system like Arc Map, I understand that the geographic coordinate is actually flat, but allows 3d data to be added to the map.  But with a cad application like AutoCAD, the opposite is true, one cannot add data to a geographic coordinate, but rather, must be in a projected one such as a state plane, to add 3d data.  I find the subject somewhat confusing and look to Esri for some explanation of this "Geographic" concept.  So I have ot ask, is it possible to have geographic coordinates for a flat map, as well as a 3d datum, and is the term really just another way to refer to a lat-long coordinate format?