λ : Elevation angle ("lamda") in radians - multiply by 57.1oto convert to degrees.
d : distance between object and observer
z1 : distance to the observer's horizon
z2 : distance to the observer's horizon
R : Radius of Earth = 3960 mi or 6378 km

Elevation Angle Formula.

Complete derivation in pdf format:Solution

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The elevation angle of a distant peak can be determined from the following Elevation Angle ("lambda) Formula:

h1 : observer's height above sea level
h2 : object's height above sea level
From the above equations the observer and object horizons can be determined and then plugged into the Elevation Angle Formula.