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

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

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

*α*Angles measured at B** – **Horizontal angle

*φ**and*

*vertical angle*

**.**

*β*

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

In triangle * ABC, *given the sine law:

Then

Also

Thus:

Ηeight of object (Ε) above ground at station A = **C _{1}E + h_{1}**

and

Ηeight of projection (D) above ground at station A = * C_{1}E + h_{1} - h_{2}* if height h

_{2}is known.