IT 327 - Schweber Chap 19 1

  

AttitudeThe longer I live, the more I realize the impact of attitude on life. Attitude, to me, is more

important than facts. It is more important than the past, than education, than money, than circumstances, than failures, than successes, than what other people think or say or do. It is more important than appearance, giftedness or skills. It will make or break a company...a church...a home. The remarkable thing is we have a choice every day regarding the attitude we will embrace for that day. We cannot change the inevitable. The only thing we can do is play on the one string we have, and that is our attitude...I am convinced that life is 10% what happens to me and 90% how I react to it. And so it is with you...we are in charge of our attitudes.

Charles Swindoll(Widely published Christian minister; 2000)

Whatever happens in the life of a person, if his attitude is right, the Lord will work that experience for that person’s good.

Elder Dennis B. NeuenschwanderFaculty Inservice, Orem Institute of Religion, Dec 14, 1996

At the center of our agency is our freedom to form a healthy attitude toward whatever circumstances we are placed in!

Elder Neal A. MaxwellDeposition of a Disciple (1976), 30–31.

IT 327 - Schweber Chap 19 2

Schweber, Chap 19:Satellite Communication, Navigation

& the Global Positioning System

Orbits

IT 327 - Schweber Chap 19 3

LEO: typically 17,000 mph

MEO: typically 12,000 mph

GEO: exactly 7070 mph

Frequency Bands

IT 327 - Schweber Chap 19 4

Factoids

IT 327 - Schweber Chap 19 5

VERY complex systemsYes, it IS rocket scienceHigh-frequency, high attenuation signals & electronicsMechanical systems that must work in extreme conditionsComplicated and expensive Earth-based systems

Typical launch weight of 100s to 1000s of lbsTypical cost of $50M to $100M (to build the satellite)Launch cost of about $10,000/lb (LEO); MEO and GEO raise that another 5x each10-year expected lifetime

Link Budget

IT 327 - Schweber Chap 19 6

How Many?(www.n2yo.com)

IT 327 - Schweber Chap 19 7

Satellite Totals - Most to LeastGeostationary 816Military 565Strela 546Space & Earth Science 475TV 375No Category 169CubeSats 146Glonass Operational 128Earth Resources 115Parus 95Iridium 92Experimental 87Globalstar 84Weather 79Amateur Radio 76Intelsat 68Tselina 65GPS Operational 64Engineering 59Westford Needles 48Rudaga 44Molniya 44Orbcomm 43Brightest 37Navy Navigation Satellite System 37Gorizont 33Tracking & Data Relay Satellite System 31Tsiklon 28Geodectic 26Yaogan 25Radar Calibration 24Disaster Monitoring 22NOAA 20Beidou Navigation System 20Tsikada 20Education 17Sfera 17Russian LEO Navigation 16GOES 15Search & Rescue 15Satellite-Based Augmentation System 14Gonets 12XM & Sirius 9ISS 8Galileo 6

TOTAL 4735

Satellite Totals - by CategoryAmateur Radio 76Beidou Navigation System 20Brightest 37CubeSats 146Disaster Monitoring 22Earth Resources 115Education 17Engineering 59Experimental 87Galileo 6Geodectic 26Geostationary 816Globalstar 84Glonass Operational 128GOES 15Gonets 12Gorizont 33GPS Operational 64Intelsat 68Iridium 92ISS 8Military 565Molniya 44Navy Navigation Satellite System 37No Category 169NOAA 20Orbcomm 43Parus 95Radar Calibration 24Rudaga 44Russian LEO Navigation 16Satellite-Based Augmentation System 14Search & Rescue 15Sfera 17Space & Earth Science 475Strela 546Tracking & Data Relay Satellite System 31Tselina 65Tsikada 20Tsiklon 28TV 375Weather 79Westford Needles 48XM & Sirius 9Yaogan 25

TOTAL 4735

Too Many?(

http://www.youtube.com/watch?v=_o7EKlqCE20

)

IT 327 - Schweber Chap 19 8

Navigation: A True Story

IT 327 - Schweber Chap 19 9

Commodore Anson and the CenturionIn September 1740, the H.M.S. Centurion set sail for the South Pacific from England under the

command of Commodore George Anson. They had no chronometer. By March, 1741, already 6 months at sea, the Centurion rounded the tip of Cape Horn, only to encounter a terrific storm that punished them for 58 days. When finally able to get a fix on their position, Anson sailed north and west for Juan Fernández Island for some desperately needed fresh water and food. When he reached the proper latitude, he had no idea which way to go – east or west. For over two months they had been unable to plot their progress, and they did not have a chronometer to allow them to determine their longitude. So on a hunch, he sailed west. But after not sighting land after four days, he decided he was already west of Juan Fernández, so they turned around and headed east.

Two days later, they sighted land, but it turned out to be the coast of Chile, under Spanish rule; they could not go there! So they executed another quick 180° turn and sailed west again. Finally, on June 9, 1741, they dropped anchor at Juan Fernández. The extra two weeks of sailing had cost Anson an additional 80 lives among his sick and ailing crew.

Longitude, by Dava Sobel (Walker & Co., 1995), pp 17-20

LORAN (LOng RAnge Navigation)

IT 327 - Schweber Chap 19 10

GPS

IT 327 - Schweber Chap 19 11

GPS

IT 327 - Schweber Chap 19 12