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{
"metadata": {
"name": "",
"signature": ""
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"chapter 10 : Sky wave propagation - The ionospheric waves"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Exa 10.1 : page 10-19"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from math import sqrt\n",
"#given data :\n",
"H=500 #in km\n",
"n=0.8 #in m\n",
"f_muf=10 #in MHz\n",
"f_muf=f_muf*10**6 #in Hz\n",
"f=10 #in MHz\n",
"f=f*10**6 #in Hz\n",
"# Formula : n=sqrt(1-81*N/f**2)\n",
"Nmax=(1-n**2)*f**2/81 #in Hz \n",
"fc=9*sqrt(Nmax) #in Hz\n",
"Dskip=2*H*sqrt((f_muf/fc)**2-1) #in Km\n",
"print \"Assuming the earth is flat the range = %0.2f km\" %Dskip\n",
"#Note : Answer in the book is wrong."
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Assuming the earth is flat the range = 1333.33 km\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Exa 10.2 : page 10-19"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#given data :\n",
"n=0.8 #in m\n",
"H=500 #in km\n",
"a=6370 #in km\n",
"D=1349.07 #in Km\n",
"f_muf=10 #in MHz\n",
"f_muf=f_muf*10**6 #in Hz\n",
"f=10 #in MHz\n",
"f=f*10**6 #in Hz\n",
"# Formula : n=sqrt(1-81*N/f**2)\n",
"Nmax=(1-n**2)*f**2/81 #in Hz \n",
"fc=9*sqrt(Nmax) #in Hz\n",
"# Formula : f_muf/fc=sqrt(D**2/(4*(H+D**2/(8*a))))+1\n",
"D1=2*(H+D**2/(8*a))*sqrt((f_muf/fc)**2-1) #in Km\n",
"Dskip=2*H*sqrt((f_muf/fc)**2-1) #in Km\n",
"print \"Assuming the earth is curved the ground range = %0.2f km\"% D1\n",
"# Answer wrong in the textbook."
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Assuming the earth is curved the ground range = 1428.57 km\n"
]
}
],
"prompt_number": 3
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Exa 10.3 : page 10-20"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from math import sqrt\n",
"#given data :\n",
"Nmax=2.48*10**6 #in cm**-3\n",
"Nmax=2.48*10**6*10**-6 #in m**-3\n",
"fc=9*sqrt(Nmax) #in MHz\n",
"print \"Critical frequency = %0.2f MHz \" %fc "
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Critical frequency = 14.17 MHz \n"
]
}
],
"prompt_number": 4
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Exa 10.4 : page 10-20"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from math import sqrt\n",
"#given data :\n",
"H=200 #in Km\n",
"D=4000 #in Km\n",
"fc=5 #in MHz\n",
"f_muf=fc*sqrt(1+(D/(2*H))**2) #in MHz\n",
"print \"MUF for the given path = %0.2f MHz \" %f_muf\n",
"#Note : Answer in the book is wrong."
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"MUF for the given path = 50.25 MHz \n"
]
}
],
"prompt_number": 5
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Exa 10.5 : page 10-20"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from math import sqrt\n",
"#given data :\n",
"#For F1 layer :\n",
"print \"For F1 layer :\" \n",
"Nmax=2.3*10**6 #in cm**3\n",
"Nmax=2.3*10**6*10**-6 #in m**3\n",
"fc=9*sqrt(Nmax) #in MHz\n",
"print \"Critical frequency = %0.2f MHz \" %fc \n",
"\n",
"#For F2 layer :\n",
"print \"For F2 layer :\" \n",
"Nmax=3.5*10**6 #in cm**3\n",
"Nmax=3.5*10**6*10**-6 #in m**3\n",
"fc=9*sqrt(Nmax) #in MHz\n",
"print \"Critical frequency = %0.2f MHz\" %fc\n",
"\n",
"#For F3 layer :\n",
"print \"For F3 layer :\" \n",
"Nmax=1.7*10**6 #in cm**3\n",
"Nmax=1.7*10**6*10**-6 #in m**3\n",
"fc=9*sqrt(Nmax) #in MHz\n",
"print \"Critical frequency = %0.2f MHz \" %fc "
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"For F1 layer :\n",
"Critical frequency = 13.65 MHz \n",
"For F2 layer :\n",
"Critical frequency = 16.84 MHz\n",
"For F3 layer :\n",
"Critical frequency = 11.73 MHz \n"
]
}
],
"prompt_number": 7
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Exa 10.6 : page 10-21"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from math import sqrt\n",
"#given data :\n",
"n=0.7 #refractive index\n",
"N=400 #in cm**-3\n",
"#Formula : n=sqrt(1-81*N/f**2)\n",
"f=sqrt(81*N/(1-n**2)) #in KHz\n",
"print \"Frequency of wave propagation = %0.2f kHz\" %f\n",
"#Note : Unit of Answer in the book is MHz. It is written by mistake. It is accurately calculated by scilab in KHz. "
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Frequency of wave propagation = 252.05 kHz\n"
]
}
],
"prompt_number": 8
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Exa 10.7 : page 10-21"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from math import sqrt\n",
"#given data :\n",
"HT=169.0 #in meter\n",
"HR=20.0 #in meter\n",
"d=4.12*(sqrt(HT)+sqrt(HR)) #in Km\n",
"print \"Maximum distance = %0.2f km \" %d \n",
"r_dash=(4/3)*6370/1000 #in Km\n",
"RadioHorizon=sqrt(2*r_dash*HT) #in Km\n",
"print \"Radio Horizon = %0.2f km \" %RadioHorizon\n",
"# Answe wrong in thetextbook."
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Maximum distance = 71.99 km \n",
"Radio Horizon = 45.03 km \n"
]
}
],
"prompt_number": 12
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Exa 10.8 : page 10-21"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from math import tan , pi, asin, cos\n",
"H=200 #in Km\n",
"Beta=20 #in Degree\n",
"a=6370 #in Km\n",
"D_flat=2*H/tan(Beta*pi/180) #in Km\n",
"print \"If earth assumed to be flat transmission path distance = %0.2f km\" %D_flat\n",
"D_curved=2*a*(90*pi/180-Beta*pi/180)-asin(a*cos(Beta*pi/180)/(a+H))\n",
"print \"If earth assumed to be curved transmission path distance = %0.2f \"%D_curved\n",
"# Answe wrong in thetextbook."
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"If earth assumed to be flat transmission path distance = 1098.99 km\n",
"If earth assumed to be curved transmission path distance = 15563.70 \n"
]
}
],
"prompt_number": 17
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Exa 10.9 : page 10-22"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from math import acos\n",
"#given data :\n",
"R=6370 #in Km\n",
"hm=400 #in Km\n",
"#Formula : d=2*R*Q=2*R*acos(R/(R+hm))\n",
"d=2*R*acos(R/(R+hm)) #in Km\n",
"print \"Maximum Range in a single range transmission = %0.2f km \" %d \n",
"# Answe wrong in thetextbook."
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Maximum Range in a single range transmission = 20011.95 km \n"
]
}
],
"prompt_number": 21
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Exa 10.10 : page 10-22"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from math import sqrt\n",
"#given data :\n",
"n=0.6 #refractive index\n",
"N=4.23*10**4 #in m**-3\n",
"#Formula : n=sqrt(1-81*N/f**2)\n",
"f=sqrt(81*N/(1-n**2)) #in Hz\n",
"print \"Frequency of wave propagation = %0.3f kHz\" %(f/1000)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Frequency of wave propagation = 2.314 kHz\n"
]
}
],
"prompt_number": 23
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Exa 10.11 : page 10-23"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from math import sqrt\n",
"#given data :\n",
"n=0.8 #refractive index\n",
"N=500 #in cm**-3\n",
"#Formula : n=sqrt(1-81*N/f**2)\n",
"f=sqrt(81*N/(1-n**2)) #in KHz\n",
"print \"Frequency of wave propagation = %0.2f kHz\" %f "
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Frequency of wave propagation = 335.41 kHz\n"
]
}
],
"prompt_number": 24
}
],
"metadata": {}
}
]
}
|
