**Known values:** Baseline distance ** AB** length, height

**of the observer, vertical angles**

*h*_{1}

*α**and*

**.**

*β***Solution:** Height of object above ground at position ** A**.

First, measure horizontal distance ** AB** and vertical angles

**and**

*α***from observer point**

*β***and**

*A*_{1}**respectively.**

*B*_{1}Then calculate vertical distance** OC_{1}:**

Thus:

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