summaryrefslogtreecommitdiff
path: root/3773/CH19
diff options
context:
space:
mode:
Diffstat (limited to '3773/CH19')
-rw-r--r--3773/CH19/EX19.1/Ex19_1.sce32
-rw-r--r--3773/CH19/EX19.2/Ex19_2.sce27
2 files changed, 59 insertions, 0 deletions
diff --git a/3773/CH19/EX19.1/Ex19_1.sce b/3773/CH19/EX19.1/Ex19_1.sce
new file mode 100644
index 000000000..f9a5562ef
--- /dev/null
+++ b/3773/CH19/EX19.1/Ex19_1.sce
@@ -0,0 +1,32 @@
+//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")
diff --git a/3773/CH19/EX19.2/Ex19_2.sce b/3773/CH19/EX19.2/Ex19_2.sce
new file mode 100644
index 000000000..6070c15c6
--- /dev/null
+++ b/3773/CH19/EX19.2/Ex19_2.sce
@@ -0,0 +1,27 @@
+//Chapter 19: The Fourier Transform Relation between Aperture Distribution and Far-field Pattern
+//Example 19-8.2
+clc;
+
+//Variable Initialization
+f = 10e9 //Frequency (Hz)
+c = 3e8 //Speed of light (m/s)
+dia = 100 //Dish diameter (m)
+aper_eff = 0.725 //Aperture efficiency (unitless)
+
+//Calculation
+wave_lt = c/f //Wavelength (m)
+hpbw = 66/(dia/wave_lt) //Half power beam width (degrees)
+
+gain = 41000/(hpbw**2) //Gain from beamwidth (unitless)
+gain_db = 10*log10(gain) //Gain from beamwidth (dBi)
+
+gain_ap = 4*(%pi**2)*(dia/2)**2*(aper_eff)/(wave_lt**2) //Gain from effective aperture(unitless)
+gain_ap_db = 10*log10(gain_ap) //Gain from effective aperture (dBi)
+
+side_lobe = -23 //First side lobe level from table (dB)
+
+//Result
+mprintf( "The Half Power Beamwidth is %.2f degrees", hpbw)
+mprintf( "\nThe gain from beamwidth is %d dBi", gain_db)
+mprintf( "\nThe gain from effective aperture is %d dBi",gain_ap_db)
+mprintf( "\nThe first side-lobe level is %d dB", side_lobe)