{ "metadata": { "name": "", "signature": "sha256:efd0e56c04d2245e98b2287a63fba67799b88e9847372ba4c5f3c4cf5de91c4c" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 11: Radars" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.1, Page number 504" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math\n", "\n", "#Variable declaraion\n", "lamda = 3.*10**-2#operating unit(cm)\n", "Pt = 600.*10**3 #peak pulse power(W)\n", "Smin = 10.**-13 #minimum detectable signal(W)\n", "Ae = 5. #m^2\n", "sigma = 20. #cross sectional area(m^2)\n", "\n", "#Calculations\n", "Rmax = ((Pt*Ae**2*sigma)/(4*math.pi*lamda**2*Smin))**0.25\n", "Rmax_nau = Rmax/1.853\n", "\n", "#Result\n", "print \"The maximum range of radar system is\",round((Rmax/1E+3),2),\"km\"\n", "print \"The maximum range of radar system in nautical miles is\",round((Rmax_nau/1E+3),2),\"nm\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The maximum range of radar system is 717.66 km\n", "The maximum range of radar system in nautical miles is 387.29 nm\n" ] } ], "prompt_number": 25 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.2, Page number 504" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#Variable declaration\n", "Pt = 250.*10**3 #peak pulse power(W)\n", "Smin = 10.**-14 #minimum detectable signal(W)\n", "Ae = 10. #m^2\n", "sigma = 2. #cross sectional area(m^2)\n", "f = 10*10**9 #frequency(Hz)\n", "c = 3*10**8 #velocity of propagation(m/s)\n", "G = 2500 #power gain of antenna\n", "\n", "#Calculations\n", "lamda = c/f\n", "Rmax = ((Pt*G*Ae*sigma)/((4*math.pi)**2*Smin))**0.25\n", "\n", "#Result\n", "print \"Maximum range possible of the antenna is\",round((Rmax/1E+3),2),\"km\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Maximum range possible of the antenna is 298.28 km\n" ] } ], "prompt_number": 30 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.3, Page number 504" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math\n", "\n", "#Variable declaration\n", "Pt = 250.*10**3 #peak pulse power(W)\n", "f = 10.*10**9 #frequency(Hz)\n", "c = 3.*10**8 #velocity of propagation(m/s)\n", "G = 4000 #power gain of antenna\n", "R = 50*10**3 #range(m)\n", "Pr = 10**-11 #minimum detectable signal(W)\n", "\n", "#Calculations\n", "lamda = c/f\n", "Ae = (G*lamda**2)/(4*math.pi)\n", "sigma = (Pr*((4*math.pi*R**2)**2))/(Pt*G*Ae)\n", "\n", "#Result\n", "print \"The radar can sight cross section area of\",round(sigma,2),\"m^2\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The radar can sight cross section area of 34.45 m^2\n" ] } ], "prompt_number": 37 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.4, Page number 505" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "#Variable declaration\n", "Pt = 400*10**3 #transmitted power(W)\n", "prf = 1500. #pulse repitiion frequency(pps)\n", "tw = 0.8*10**-6 #pulse width(sec)\n", "c = 3.*10**8 #velocity of propagation(m/s)\n", "\n", "#Calculations\n", "#Part a\n", "Run = c/(2*prf)\n", "\n", "#Part b\n", "dc = tw/(1/prf)\n", "\n", "#Part c\n", "Pav = Pt*dc\n", "\n", "#Part d\n", "n1 = 1\n", "BW1 = n1/tw\n", "\n", "n2 = 1.4\n", "BW2 = n2/tw\n", "\n", "#Results\n", "print \"The radar's unambiguous range is\",round((Run/1E+3),2),\"km\"\n", "print \"The duty cycle for radar is\",dc\n", "print \"The average power is\",round(Pav,2),\"W\"\n", "print \"Bandwidth range for radar is\",(BW1/1E+6),\"MHz and\",(BW2/1E+6),\"MHz\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The radar's unambiguous range is 100.0 km\n", "The duty cycle for radar is 0.0012\n", "The average power is 480.0 W\n", "Bandwidth range for radar is 1.25 MHz and 1.75 MHz\n" ] } ], "prompt_number": 47 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.5, Page number 505" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math\n", "\n", "#Variable declaration\n", "Pt = 2.5*10**6 #power output(W)\n", "D = 5 #antenna diameter(m)\n", "sigma = 1 #cross sectional area of target(m^2)\n", "B = 1.6*10**6 #receiver bandwidth(Hz)\n", "c = 3.*10**8 #velocity of propagation(m/s)\n", "Nf = 12. #noise figure(dB)\n", "f = 5*10**9 #frequency(Hz)\n", "\n", "#Calculations\n", "lamda = c/f\n", "F = 10**(Nf/10)\n", "Rmax = 48*(((Pt*D**4*sigma)/(B*lamda**2*(F-1)))**0.25)\n", "\n", "#Result\n", "print \"The maximum detection range is\",round(Rmax,2),\"km\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The maximum detection range is 558.04 km\n" ] } ], "prompt_number": 57 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.6, Page number 506" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "import math \n", "\n", "#Variable declaration\n", "Rmax = 30 #maximum range of radar(km)\n", "n = 50 #no. of echos\n", "\n", "#Calculation\n", "R = Rmax*math.sqrt(math.sqrt(n))\n", "\n", "#After doubling the power\n", "R1 = math.sqrt(math.sqrt(2))\n", "\n", "#Results\n", "print \"Maximum range with echoing of 50 times is\",round(R,2),\"km\"\n", "print \"If transmitter power is doubled, range would increase by a factor of\",round(R1,2)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Maximum range with echoing of 50 times is 79.77 km\n", "If transmitter power is doubled, range would increase by a factor of 1.19\n" ] } ], "prompt_number": 61 } ], "metadata": {} } ] }