I've discovered, that I have no idea, how height is usually represented in GIS.
For example, let's say we have software, that lets you create a mission plan for an UAV such as
- take off
- go to point x1
- go to point x2
Where "point" is represented by
Latitude and longitude are "intuitive" (there's no question about what they actually mean, once you select a geodetic datum). However, height is not. How can one represent it? Things, that come to mind:
- height in relation to takeoff point
- height in relation to "sea level"
- height in relation to some other reference point
- distance from the center of the Earth (I mean, why not?)
Is there some canonical way of representing heights, preferrably, a way that is not tied to the problem domain (UAVs, etc)?
Of course, I am ready to accept an answer, that will point me to some reference / literature on the topic, instead of answering the question directly. I am, in fact, quite ignorant about GIS, so I don't have much of an idea even which keywords to search for.