What is the aeroplane flying height to obtain the average scale of the photograph equal to 1/7200? (Ground surface elevations vary from 160 m to 430 m and focal length of the camera lens is 153 mm)

Concept: 

Scale of a Photograph:
The scale of a photograph depends on flying height of the photograph, the focal length of the camera and the elevation of ground level with respect to mean sea level.

\({\rm{S}} = \frac{{\rm{f}}}{{{\rm{H}} - {\rm{h}}}}\)

Where,

f = Focal length of a camera, H = Flying height

h = Elevation of object or ground level above M.S.L

Calculation:

Given,

f = 153 mm, H = ?, h = (160 + 430)/2 = 295 m, S = 1/7200

\({\rm{S}} = \frac{{\rm{f}}}{{{\rm{H}} - {\rm{h}}}}\)

\({\rm\frac{1}{7200}} = \frac{{\rm{153\times10^{-3}}}}{{{\rm{H}} - {\rm{295}}}}\)

⇒ H = 1396.6 m