Baseline distance AB length, height h1 of the observer at points A and B.
Vertical angles measured at A – α1 and a2.
Vertical angles measured at B – β1 and β2.
Solution: Height of object Η.
First, measure horizontal distance AB and vertical angles α1, α2 and β1, β2 from observer points A1 and B1 respectively.
Then calculate vertical distances C1E and C1O.
Combining the previous equations: