4.12.4. Height determination

Try these first

1. 1.

   What is parallax?

   Hint

   Think about how your point of view changes when you move.

2. 2.

   How can height be approximately calculated?

   Hint

   Recall the process of comparing the images.

3. 3.

   What is the primary purpose of using a stereo pair in aerial photographs?

   • To enhance image quality
   • To determine height and depth
   • To improve color accuracy

   Hint

   Think about what we can determine from the perspective capability of two images.

4. 4.

   True or False: The height of an object is inversely proportional to the flying height.

   • True
   • False

   Hint

   What happens to the displacement when flying higher?

5. 5.

   Calculate the height of point C if the known elevation of point A is 70 m, the parallax difference (Δp) is 10 mm, and the flying height is 300 m.

   Hint

   Use the given equation and break down the calculation step by step.

6. 6.

   Aerial photographs are captured with a known air base of 1000 m. If the estimated parallax difference is calculated to be 8 mm, derive the approximate height of the object if the flying height was 400 m.

   Hint

   Ensure you understand how air base and flying height affect parallax.