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//Chapter 19: The Fourier Transform Relation between Aperture Distribution and Far-field Pattern
//Example 19-8.1
clc;
//Variable Initialization
gal_ext = 400000 //Extent of galaxy (light-years)
alpha = 0.032 //Extent of galaxy (degrees)
f = 5e9 //Frequency (Hz)
a = 36e3 //Maximum VLA Spacing (m)
c = 3e8 //Speed of light (m/s)
wid = 0.03 //Width of image (degrees)
hei = 0.008 //Height of image (degrees)
flux_den = 2.5e-23 //Average flux density (W/m^2)
bw = 1e9 //Bandwidth (Hz)
//Calculations
dist = gal_ext/sin(alpha*%pi/180) //Distance to the galaxy (light-years)
dist_m = dist*(365*24*3600*c)
wave_lt = c/f //Wavelength (m)
a_lambda = a/wave_lt //Spacing in wavelength (unitless)
pix_size = 51/a_lambda //Resolution or pixel size (degrees)
pix_size_arc = pix_size*3600 //Pixel size (arc seconds)
area = wid*hei //Area of image (square degrees)
area_arc = area*(3600**2) //Area of image (arc seconds)
num_pix = area_arc/pix_size_arc**2 //Number of pixels
rad_pow = flux_den*4*%pi*(dist_m**2)*bw
//Result
disp(dist,"The distance to the galaxy in light years:")
disp(pix_size_arc,"The resolution or pixel size in arc seconds")
disp(num_pix,"The number of pixels is")
disp( rad_pow,"The radio power of the galaxy in W")
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