If the mean elevation of the terrain to be mapped is 1,400 ft above sea level and the vertical photography is to be taken with a 6-in focal length camera at an elevation of 4,400 ft, what is the nominal map scale when utilizing an 8 to 1 plotting ratio?
Explanation
Answer: B- If the mean elevation of the terrain to be mapped is 1,400 ft above sea level and the vertical photography is to be taken with a 6-in focal length camera at an elevation of 4,400 ft, the nominal map scale when utilizing an 8 to 1 plotting ratio is 1 in = 62.5 ft.
Solution
Use the scale equation S = f/H-h
Where S = scale (in/ft)
f = focal length of camera (in)
H = flying height above datum (ft)
h = average terrain elevation (ft)
H-h = 4,400 - 1,400 ft = 3,000
Scale = 6 in / 3,000 ft
1 in = 500 ft
Scale is 1 in / 500 ft
Plotting Ratio: 8 to 1
Nominal Map Scale 1 in = 500/8 ft
1 in = 62.5 ft
