{ "metadata": { "name": "" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 3: Satellite Launch and In-Orbit Operations" ] }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 3.1, page no-72" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#Variable Declaration\n", "Az=85 # Azimuth angle of injection point\n", "l=5.2 # latitude of launch site\n", "\n", "\n", "#Calculation\n", "cosi=math.sin(Az*math.pi/180)*math.cos(l*math.pi/180)\n", "i=math.acos(cosi)\n", "i=i*180.0/math.pi\n", "\n", "\n", "#Result\n", "print(\"Inclination angle attained, i=%.1f\u00b0\"%i)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Inclination angle attained, i=7.2\u00b0\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 3.2, page no-73" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#Variable Declaration\n", "delta_i=7 #orbital plane inclination\n", "V=3000 #velocity of satellite in circularized orbit\n", "\n", "\n", "#Calculation\n", "vp=2*V*math.sin(delta_i*math.pi/(2*180))\n", "\n", "\n", "#Result\n", "print(\"Velocity thrust to make the inclination 0\u00b0 = %.0f m/s\"%vp)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Velocity thrust to make the inclination 0\u00b0 = 366 m/s\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 3.3, page no-73" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Variable Declaration\n", "mu=39.8*10**13 # Nm^2/kg\n", "P=7000.0*10**3 # Perigee distance in m\n", "e=0.69 # eccentricity of eliptical orbit\n", "w=60.0/2 # angle made by line joing centre of earth and perigee with the line of nodes\n", "\n", "\n", "#Calculation\n", "k=(e/math.sqrt(1+e))\n", "k=math.floor(k*100)/100\n", "v=2*(math.sqrt(mu/P))*k*math.sin(w*math.pi/180.0)\n", "\n", "\n", "#Result\n", "print(\"The velocity thrust required to rotate the perigee point\\n by desired amount is given by, v=%.1f m/s = %.3fkm/s\"%(v,v/1000.0))\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The velocity thrust required to rotate the perigee point\n", " by desired amount is given by, v=3996.4 m/s = 3.996km/s\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 3.4, page no-74" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#Variable Declaration\n", "A=15000*10**3 #Original apogee distance\n", "A1=25000*10**3 # Raised opogee distance\n", "P=7000*10**3 # Perigee Distance\n", "mu=39.8*10**13 #Nm**2/kg\n", "\n", "\n", "#Calculation\n", "A_d=A1-A\n", "v=math.sqrt((2*mu/P)-(2*mu/(A+P)))\n", "del_v=A_d*mu/(v*(A+P)**2)\n", "\n", "\n", "#Result\n", "print(\"required Thrust velocity Delta_v = %.1f m/s\"%del_v)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "required Thrust velocity Delta_v = 933.9 m/s\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 3.5, page no-75" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#Variable Declaration\n", "A=15000.0*10**3 # Original apogee distance\n", "A1=7000.0*10**3 # Raised opogee distance\n", "P=7000.0*10**3 # Perigee Distance\n", "mu=39.8*10**13 # Nm^2/kg\n", "\n", "\n", "#Calculation\n", "A_d=A-A1\n", "v=math.sqrt((2*mu/P)-(2*mu/(A+P)))\n", "del_v=A_d*mu/(v*(A+P)**2)\n", "\n", "#Result\n", "print(\"required Thrust velocity Delta_v = %.1f m/s\"%del_v)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "required Thrust velocity Delta_v = 747.1 m/s\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 3.6, page no-76" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Variable Declaration\n", "A=15000.0*10**3 # Original apogee distance\n", "A1=16000.0*10**3 # Raised opogee distance\n", "P=7000.0*10**3 # Perigee Distance\n", "mu=39.8*10**13 # Nm**2/kg\n", "\n", "\n", "#Calculation\n", "A_d=A1-A\n", "v=math.sqrt((2*mu/P)-(2*mu/(A+P)))\n", "v=v*P/A\n", "del_v=A_d*mu/(v*(A+P)**2)\n", "\n", "#Result\n", "print(\"required Thrust velocity Delta_v = %.1f m/s\"%del_v)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "required Thrust velocity Delta_v = 200.1 m/s\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 3.7, page no-77" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#Variable Declaration\n", "R=6378.0*10**3 # Radius of earth\n", "mu=39.8*10**13 # Nm**2/kg\n", "r1=500.0*10**3 # original orbit from earths surface\n", "r2=800.0*10**3 # orbit to be raised to thisdistance\n", "\n", "\n", "#Calculation\n", "R1=R+r1\n", "R2=R+r2\n", "delta_v=math.sqrt(2*mu*R2/(R1*(R1+R2)))-math.sqrt(mu/R1)\n", "delta_v_dash=math.sqrt(mu/R2)-math.sqrt(2*mu*R1/(R2*(R1+R2)))\n", "\n", "\n", "#Result\n", "print(\"Two thrusts to be applied are,\\n Delta_v = %.2f m/s \\n Delta_v_dash = %.2f m/s\"%(delta_v,delta_v_dash))\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Two thrusts to be applied are,\n", " Delta_v = 80.75 m/s \n", " Delta_v_dash = 79.89 m/s\n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 3.8, page no-97" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#Variable Declaration\n", "H=36000.0 # Height of geostationary satellite from the surface of earth\n", "R=6370.0 # Radius of earth in km\n", "\n", "\n", "#Calculation\n", "k=math.acos(R/(R+H))\n", "#k=k*180/%pi\n", "k=math.sin(k)\n", "k=math.ceil(k*1000)/1000\n", "d=2*(H+R)*k\n", "\n", "\n", "#Result\n", "print(\"Maximum line-of-sight distance is %.2f km\"%d)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Maximum line-of-sight distance is 83807.86 km\n" ] } ], "prompt_number": 8 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 3.9, page no-98" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#Variable Declaration\n", "H=36000.0 # Height of geostationary satellite from the surface of earth\n", "R=6370.0 # Radius of earth in km\n", "theta=20.0 # angular separation between two satellites\n", "\n", "\n", "#Calculation\n", "D=(H+R)\n", "k=math.ceil(math.cos(theta*math.pi/180.0)*100)/100\n", "d=math.sqrt(2*D**2*(1-k))\n", "\n", "\n", "#Result\n", "print(\"The line-of-sight distance is %.4f km\"%d)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The line-of-sight distance is 14677.3985 km\n" ] } ], "prompt_number": 9 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 3.10, page no-98" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Variable Declaration\n", "\n", "#IntelSat-VI location= 37 W\n", "# IntelSat-VII location=74 E\n", "theta=37+74 # angular separation between two satellites\n", "D=42164.0 # circular equilateral geostationary orbit in km\n", "\n", "\n", "#Calculation\n", "k=math.cos(math.pi*theta/180.0)\n", "#printf(\"%f\\n\",k)\n", "k=-0.357952\n", "d=math.sqrt(2*D**2*(1-k))\n", "\n", "\n", "#Result\n", "print(\"Inter-satellite distance is %.2f km\"%d)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Inter-satellite distance is 69486.27 km\n" ] } ], "prompt_number": 10 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 3.11, page no-99" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "theta_l=30.0 # earth station's location 30\u00b0W longitude\n", "theta_s=50.0 # satellite's location 50\u00b0W longitude\n", "theta_L=60.0 # earth station's location 60\u00b0N latitude\n", "r=42164.0 # orbital radius of the satellite in km\n", "R=6378.0 # Earth's radius in km\n", "\n", "A_dash=math.atan((math.tan(math.pi*(theta_s-theta_l)/180.0))/math.sin(math.pi*60/180.0))\n", "A_dash=A_dash*180/math.pi\n", "A=180+A_dash #Azimuth angle\n", "\n", "x=(180/math.pi)*math.acos(math.cos(math.pi*(theta_s-theta_l)/180.0)*math.cos(math.pi*theta_L/180))\n", "y=r-math.ceil(R*(math.cos(math.pi*(theta_s-theta_l)/180.0)*math.cos(math.pi*theta_L/180)))\n", "z=R*math.sin(math.pi*x/180)\n", "E=(math.atan(y/z)*180/math.pi)-x\n", "print(\"Azimuth angle =%.1f\u00b0\\n Elevation angle =%.1f\u00b0\"%(A,E))\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Azimuth angle =202.8\u00b0\n", " Elevation angle =19.8\u00b0\n" ] } ], "prompt_number": 11 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 3.12, page no-100" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#Variable Declaration\n", "theta_l=60.0 #earth station's location 60\u00b0W longitude\n", "theta_s=105.0 #satellite's location 105\u00b0W longitude\n", "theta_L=30.0 #earth station's location 30\u00b0N latitude\n", "\n", "theta_l1=90.0 #earth station's location 90\u00b0W longitude\n", "theta_s1=105.0 #satellite's location 105\u00b0W longitude\n", "theta_L1=45.0 #earth station's location 45\u00b0N latitude\n", "\n", "c=3*10**8 # speed of light\n", "r=42164.0 # orbital radius of the satellite in km\n", "R=6378.0 # Earth's radius in km\n", "\n", "\n", "#Calculation\n", "\n", "x=(180/math.pi)*math.acos(math.cos(math.pi*(theta_s-theta_l)/180)*math.cos(math.pi*theta_L/180))\n", "y=r-math.ceil(R*(math.cos(math.pi*(theta_s-theta_l)/180)*math.cos(math.pi*theta_L/180)))\n", "z=R*math.sin(math.pi*x/180)\n", "E=(math.atan(y/z)*180/math.pi)-x\n", "\n", "x1=(180/math.pi)*math.acos(math.cos(math.pi*(theta_s1-theta_l1)/180)*math.cos(math.pi*theta_L1/180))\n", "y1=r-math.ceil(R*(math.cos(math.pi*(theta_s1-theta_l1)/180)*math.cos(math.pi*theta_L1/180)))\n", "z1=R*math.sin(math.pi*x1/180)\n", "E1=(math.atan(y1/z1)*180/math.pi)-x1\n", "E1=math.floor(E1)\n", "\n", "#calculation of slant range dx\n", "k=(R/r)*math.cos(math.pi*E/180)\n", "k=(180/math.pi)*math.asin(k)\n", "k=k+E\n", "k=math.sin(math.pi*k/180)\n", "k=math.ceil(k*1000)/1000\n", "#k=k+E\n", "#k=sin(k)\n", "dx=(R)**2+(r)**2-(2*r*R*k)\n", "dx=math.sqrt(dx)\n", "\n", "\n", "#calculation of slant range dy\n", "k1=(R/r)*math.cos(math.pi*E1/180)\n", "k1=(180/math.pi)*math.asin(k1)\n", "k1=k1+E1\n", "k1=math.floor(k1)\n", "k1=math.sin(math.pi*k1/180)\n", "k1=math.ceil(k1*1000)/1000\n", "dy=(R)**2+(r)**2-(2*r*R*k1)\n", "dy=math.sqrt(dy)\n", "\n", "tr=dy+dx\n", "delay=tr*10**6/c\n", "x=50\n", "td=delay+x\n", "\n", "\n", "#Result\n", "print(\"Elevation angle, Ex =%.1f\u00b0\"%E)\n", "print(\"\\n Elevation angle, Ey =%.1f\u00b0\"%math.floor(E1))\n", "print(\"\\n Slant range dx of the earth station X is dx=%.2fkm\"%dx)\n", "print(\"\\n Slant range dy of the earth station Y is dy=%.1fkm\"%dy)\n", "print(\"\\n Therefore, total range to be covered is %.2fkm\"%tr)\n", "print(\"\\n propagation delay=%.2fms\"%delay)\n", "print(\"\\n\\n Time required too transmit 500 kbs of information at \\n a transmisssion speed of 10Mbps is given by 500000/10^7=%.0fms\"%(500000000.0/10**7))\n", "print(\"\\n\\n Total Delay= %.2fms\"%td)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Elevation angle, Ex =30.3\u00b0\n", "\n", " Elevation angle, Ey =36.0\u00b0\n", "\n", " Slant range dx of the earth station X is dx=38584.76km\n", "\n", " Slant range dy of the earth station Y is dy=38100.8km\n", "\n", " Therefore, total range to be covered is 76685.57km\n", "\n", " propagation delay=255.62ms\n", "\n", "\n", " Time required too transmit 500 kbs of information at \n", " a transmisssion speed of 10Mbps is given by 500000/10^7=50ms\n", "\n", "\n", " Total Delay= 305.62ms\n" ] } ], "prompt_number": 12 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 3.13, page no-102" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#Variable Declaration\n", "da=38000.0 # slant range of satellite A\n", "db=36000.0 # slant range of satellite B\n", "beeta=60.0 # difference between longitudes of two satellites\n", "R=42164.0 # radius of the orbit of satellites\n", "\n", "\n", "#Calculation\n", "theta=(da**2+db**2-2*(R**2)*(1-math.cos(math.pi*beeta/180)))/(2*da*db)\n", "theta=(180/math.pi)*math.acos(theta)\n", "d=math.sqrt(2*(R**2)*(1-math.cos(math.pi*beeta/180)))\n", "\n", "\n", "#Result\n", "print(\"Angular spacing between two satellites viewed by earth station is,\\n theta= %.1f\u00b0\"%theta)\n", "print(\"\\nInter-satellite distance , d=%.0fkm\"%d)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Angular spacing between two satellites viewed by earth station is,\n", " theta= 69.4\u00b0\n", "\n", "Inter-satellite distance , d=42164km\n" ] } ], "prompt_number": 13 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 3.14, page no-107" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#Variable Declaration\n", "r=42164.0 # orbital radius of the satellite in km\n", "R=6378.0 # Earth's radius in km\n", "\n", "#refer to Figure 3.53\n", "\n", "#Calculation\n", "\n", "#for E=0\u00b0\n", "alfa=math.asin(R/r)*(180/math.pi)\n", "alfa=math.floor(alfa*10)/10\n", "theta=90-alfa\n", "#in the right angle triangle OAC,\n", "k=math.sin(math.pi*alfa/180)\n", "k=math.floor(k*1000)/1000\n", "oc=R*k\n", "oc=math.ceil(oc*10)/10\n", "A=2*math.pi*R*(R-oc)\n", "\n", "\n", "#for E=10\u00b0\n", "E=10\n", "alfa1=math.asin((R/r)*math.cos(math.pi*E/180))*(180/math.pi)\n", "#alfa1=ceil(alfa1*100)/100\n", "theta1=90-alfa1-E\n", "#in the right angle triangle OAC,\n", "k1=math.sin(math.pi*(alfa1+E)/180)\n", "k1=math.floor(k1*1000)/1000\n", "oc1=R*k1\n", "oc1=math.floor(oc1*10)/10\n", "A1=2*math.pi*R*(R-oc1)\n", "\n", "\n", "#Result\n", "print(\"for E=0\u00b0,\\n covered surface area is %.1f km^2\"%A)\n", "print(\"\\n\\n for E=10\u00b0,\\n covered surface area is %.1f km^2\"%A1)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "for E=0\u00b0,\n", " covered surface area is 216997546.7 km^2\n", "\n", "\n", " for E=10\u00b0,\n", " covered surface area is 174314563.3 km^2\n" ] } ], "prompt_number": 15 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 3.15, page no-108" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#variable declaration\n", "theta=30 #satellite inclination to the equitorial plan\n", "#the extreme latitudes covered in northern and southern hemisphere are the same as orbit inclination\n", "\n", "print(\"Extreme Northern latitude covered = %.0f\u00b0 N\"%theta)\n", "print(\"\\n Extreme Southern latitude covered = %.0f\u00b0 S\"%theta)\n", "print(\"\\n\\n In fact, the ground track would sweep\\n all latitudes between %d\u00b0N and %d\u00b0S\"%(theta,theta))\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Extreme Northern latitude covered = 30\u00b0 N\n", "\n", " Extreme Southern latitude covered = 30\u00b0 S\n", "\n", "\n", " In fact, the ground track would sweep\n", " all latitudes between 30\u00b0N and 30\u00b0S\n" ] } ], "prompt_number": 16 } ], "metadata": {} } ] }