What is the term for Zero elevation?

Question

Let say for a level transmitter

Answer 1

Sea level.

Answer 2

I will give you the wiki def in the link, however, as a working inventor/scientist, my opinion of the definition is somewhat different than what is listed at the link...
If you were to fire a cannon, and you had the barrel level with (LOS) < Line Of Sight = level plane to earths visible surface, you could say that is zero elevation, however, it would best be said there was zero DECLINATION.
Think of the whole thing like a compass. When your facing and the needle is pointing directly north, thats zero (or depending on your definition, 360 Degrees/Zero Degrees) From there, like hands on a clock, if it was pointing east, or 15 minutes after the hour, that would be 90 degrees. If you turned in a half circle with your compass, you would be facing 180 degrees.
If you started at zero and turned around in a full circle, you would have just done a "360"...
Now, you get the idea of "direction" or bearings......
Now imagine taking you compass and turning it on its side? Try it. Maybe that makes sense, hope so... elevation , think of it , that if you were going to try to fire a cannon, 45 degrees LOS, would be the most normal angle to begin with. What would happen if you fired your cannon at a 90 degree angle? RUNNN!!! :) Your shell, or cannon ball is gonna come down on your head, hehe :) Best, Dave (when talking about the cannon ball at 90 degrees, that could be interpreted as turning right, what I meant to impress was the idea of using scale, or measuring devices, like a square or thermometer, etc.. when I said 90 deg. with the cannon, i meant it as in still keeping with the compass but parallel, the compass is intended to be used in the horizontal plane.) sorry if I confused you ;( Best, Dave

Answer 3

Interesting article, but I would like to see some more evidence that this is indeed the case. The scientists have all made modifications to the data in an unblinded manner, so there can be little doubt that they are indeed adding bias, though unintentionally. I am not sure how much of an effect, if any their unintentional biasing of the data causes, but if they are intentionally doing so, they should be in jail after the billions of taxpayer's dollars they have used. Once again I would need to see more evidence.

Answer 4

Ditto to Dapper.

It is sea level, and is often the dataum for topographic surveys. Thus if the elevation of a mountain peak is 14,000', that means 14,000 ft above sea level.

Answer 5

urm..
1) Reference point?
2) Starting point?
3) Staionary point?
4) Equilibrium?