Calculation example - Calculate the height of an object when its base is inaccessible

Calculate the height of an object from a baseline when its projected position to the ground is inaccessible. Case scenario when baseline AB is level and collinear with object.

Known values: Baseline distance AB length, height h₁ of the observer, vertical angles α and β.

Solution: Height of object above ground at position A.

First, measure horizontal distance AB and vertical angles α and β from observer point A₁ and B₁ respectively.

Then calculate vertical distance OC₁:

Thus:

Finally, calculate height of object above ground at station A: