I'm trying to grasp the basics of GIS but my literature seems to leave out some of the basic concepts (or it's just very vague).
What units are usually used for coordinates in a geographic coordinate system (such as WGS84) and what units are used for coordinates in a projected coordinate system?
I believe the answer to the first part of the question is degrees, minutes, seconds or sometimes decimal degrees (depending on the level of precision).
What about projected coordinate systems?
Best Answer
A geographic projection will always be in degrees (or possibly radians) (the distinction between decimal and dms is one of formatting).
A projected crs can be in any units the designer wants, often meters or some kind of feet but I have seen "German Legal Metres", chains and many other weird options.