Question

Write a short note on scale of Aerial Photograph.

Answer 1

The scale of an aerial photograph is a crucial aspect, as it determines the level of detail captured. The scale is expressed as a representative fraction (R.F.) that compares the distance on the photograph to the actual distance on the ground. It depends on two factors:

1. Camera Focal Length (Cf): The distance between the camera lens and the film/sensor.
2. Altitude or Elevation of the Camera (H): The height at which the camera is flown above the ground.

The formula used to calculate the scale (R.F.) is:

Representative Fraction (R.F.) = `"Camera Focal Length (Cf)"/"Elevation of Camera (H)"`

For example, if the camera focal length is 2 metres and the camera elevation is 20,000 metres, the scale would be: 

R.F. = `2/(20,000) = 1/(10,000)`

This means that 1 unit in the photograph represents 10,000 units on the ground.