**Known values:**

Baseline distance ** AB** length, height

**of the observer at points A and B.**

*h*_{1}Angles measured at A – Horizontal angle ** θ** vertical angle

*α**to object, and vertical angle*

*δ**slope of ground.*

Angles measured at B** – **Horizontal angle

*φ**and*

*vertical angle*

**.**

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

First, calculate horizontal distance *A _{1}B_{2}. *

In triangle A_{1}C_{1}B_{2}, given the sine law:

In triangle A_{1}C_{1}E:

Then:

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

Combining the previous:

** **