Answer :
Answer:
Minimum aperture diameter, B = [tex]7.96\times 10^{-9} = 7.96 mm[/tex]
Given:
Altitude of airplane, l = 29 Km = 29000 m
width, d = 2.0 m
wavelength, [tex]\lambda = 450 nm = 450\times 10^{-9}[/tex]
Solution:
By Reighley criterion, Angle of resolution [tex]\theta [/tex] is given by:
[tex]\theta_{min} = 1.22\frac{\lambda}{B}[/tex] (1)
Also, separation angle or limiting angle, [tex]\theta_{min} = \frac{\lambda}{w}[/tex] (2)
From eqn (1) and (2):
[tex]B = 1.22\frac{\lambda\times l}{w}[/tex]
[tex]B = 1.22\frac{450\times 10^{-9}\times 29000}{2}[/tex]
B = 7.96 mm