1.20.1. Finding height of an object which is accessible

Try these first

1. 1.

   What is the first step in measuring the height of a tower?

   Hint

   Recall the importance of line of sight.

2. 2.

   Define vertical angle.

   Hint

   Think about angles in elevation.

3. 3.

   What formula do you use to find height above the instrument axis?

   • H = D tan(α)
   • h = D tan(α)
   • H = h + h_s

   Hint

   Consider which equation defines the height.

4. 4.

   True or False: The distance D is not necessary to calculate height.

   • True
   • False

   Hint

   Recall the relationship between angle, height, and distance.

5. 5.

   You are standing 50 meters from a building. The vertical angle to the top is measured at 35 degrees. If your instrument is 1.8 meters above the BM, calculate the height of the building.

   Hint

   First, find the height above the instrument axis.

6. 6.

   If the instrument is set up at two points 100 meters apart on level ground, measuring the heights of two towers with angles of 20° and 25° from each point, how do you calculate the height of the towers?

   Hint

   You will need to consider the different positions and angles when calculating each height.