4.12.3. Measurement of absolute parallax

Try these first

1. 1.

   Define absolute parallax in your own words.

   Hint

   Think about how it relates to distances.

2. 2.

   What instrument is often used to measure parallax in photographs?

   Hint

   Consider the tools used in photogrammetry.

3. 3.

   What is absolute parallax?

   • A measurement of height
   • The difference in distances from principal points
   • A type of camera

   Hint

   Focus on what defines this term in aerial photography.

4. 4.

   True or False: Absolute parallax is only defined for vertical photographs.

   • True
   • False

   Hint

   Remember the general definition of parallax.

5. 5.

   If point A is 15 mm away from the principal point on the left photo and point B is 40 mm away on the right, what is the absolute parallax?

   Hint

   Pay attention to the distances and their signs.

6. 6.

   Discuss how you would theoretically improve the accuracy of height determination from parallax measurements.

   Hint

   Explore methods used in photogrammetry to ensure precision.