On 7/26/2010 1:12 PM, Terje Mathisen wrote:

I believe that h/2R term is significantly smaller than the normal
atmospheric effects, i.e. today I can see features on the other side of
the Oslo fjord that I know should be below the horizon. :-)


You betcha! It's usual to take the notional radius of the Earth as 20%
bigger than the real radius (which of course itself varies because of
the oblateness of the spheroid) to account for refraction.

As usual, there is a wiki on the topic.

Brian W