italia, I think by now it's for you to figure out.
ft,
Originally Posted by ft
There seems to be a misunderstanding ..... that geoid undulation has to do with the elevation of the surface of the earth. ...It doesn't.
Guilty as indirectly charged of oversimplifying. Your contributions suggest there are at least three definitions, with two of them being TAS in the "tangential", corrected for ("tangential") wind. "Tangential" is orthogonal to "vertical", and the vertical can either be defined as (a) normal to the surface of the model (the "reference ellipsoid", WGS84, or national ellipsoid, or some other mathematical model) or as (b) "true" vertical (the direction in which the gravity vector actually points).
As to the difference between (a) and (b), I am (passively) informed that
Originally Posted by Kayton, p25
The angle between the gravity vector and the normal to the ellipsoid, the deflection of the vertical, is commonly less than 10 seconds of arc and is rarely greater than 30 seconds of arc
referencing a U.S. Defence Mapping Agency report from 1959. You said in
this post that this makes a practical difference. Can you maybe give an example that illustrates this well?
PBL