4.8.27. Scale

Try these first

1. 1.

   What does scale in photogrammetry refer to?

   Hint

   Think about how distances relate between a photo and actual map.

2. 2.

   Define focal length.

   Hint

   Consider the camera's lens positioning.

3. 3.

   What is the scale of an aerial photograph defined as?

   • A distance on the photograph to a distance on the ground
   • Focal point measurement
   • Temperature measurement

   Hint

   Think about distances compared to what you see in photographs.

4. 4.

   True or False: The scale of a photograph remains constant regardless of terrain elevation.

   • True
   • False

   Hint

   Remember how different heights might impact photography results.

5. 5.

   You have a photograph taken at a flying height of 1500 m using a camera with a focal length of 75 mm. Calculate the scale of the photograph and discuss how it might change if the average elevation of objects in view is raised by 20 m.

   Hint

   Recalculate with adjusted height; elevation will always make scale change.

6. 6.

   Consider two points on differing elevations, point A at 15 m and point B at 25 m above sea level. Calculate their respective scales if photographed from a height of 1000 m with a 50 mm lens.

   Hint

   Do each calculation separately and notice how their differences arise from their heights.