Lecture 12: The Last One

1. Lecture 12: The Last One A Few Observations Course Surveys Introduction to Engineering Electronics K. A. Connor

2. The Past: Theodore Judah • My Favorite RPI Alum from the 19th Century • Compare with Washington Roebling, the builder of the Brooklyn Bridge Introduction to Engineering Electronics K. A. Connor

3. Theodore Judah • Rensselaer student in 1837 • Transcontinental Railroad Visionary 1826-1863 • Theodore Judah was known as "Crazy Judah" because of his single-minded passion for driving a railroad through the Sierra Nevada mountains. • His advocacy and enthusiasm for the project in California and in Washington, D.C., made possible America's first transcontinental route. • Judah constructed the first railroad in California, helped organize the Central Pacific Railroad Co., surveyed routes across the Sierra Nevada, and served as the railroad's agent in Washington, D.C. • Where can you find his picture? Introduction to Engineering Electronics K. A. Connor

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5. Theodore Judah • Judah is given credit for developing the first practical plan for the Central Pacific RR. • Financial backing for the RR came from the Big Four: Mark Hopkins, Collis Huntington, Charles Crocker and Leland Stanford, • Leland Stanford was born in Watervliet, NY in 1824. It was called West Troy at the time. He and his wife founded a reasonably good school in California and named it after their deceased son. Introduction to Engineering Electronics K. A. Connor

6. The Future?Iridium – An Entertaining Failure or Now on the Road to Success? • What are some of the limitations of present mobile phone systems? • One of the primary problems is that service tends to be limited to higher population areas. • If you are a Sprint customer (in spite of the annoying adds), you have the coverage shown in this map. Introduction to Engineering Electronics K. A. Connor

7. Iridium • 1987: Two Motorola engineers envision a constellation of low orbiting satellites. • 1990: The Iridium System is announced. • 1995: FCC License granted • 1998: Constellation of 66 satellites successfully launched. • 1999: Chapter 11 • 2002: Licenses, etc. assigned to New Iridium Note: Financing was several billion dollars Introduction to Engineering Electronics K. A. Connor

8. Iridium Flares – Fun With Satellites • The Iridium satellites are relatively small telecommunications satellites in a low Earth orbit. • Each satellite has three main mission antennas (MMAs), which are flat, highly reflective surfaces, that can reflect the Sun's rays to an observer on the ground when the geometry is correct. Introduction to Engineering Electronics K. A. Connor

9. Iridium Flares – Fun With Satellites • The satellite's attitude is controlled so that the long axis remains vertical, with one MMA always pointing forwards. Given this knowledge of the attitude, together with the orbital position of the satellite and the Sun and observer's location, it is possible to calculate the angle between the direction to the observer from the satellite and the line of a perfect reflection of the Sun. This is the so-called "mirror angle" and determines the magnitude of the flare. Introduction to Engineering Electronics K. A. Connor

10. Iridium Flares • Heavens Above is an extensive website with information on tracking objects in space, notably including Iridium Satellites. Introduction to Engineering Electronics K. A. Connor

11. Iridium Flares • In the main Heavens Above webpage, select your location either exactly by longitude and latitude or from their extensive database. • Choose United States, then Sycaway (where I live) Latitude: 42.742, Longitude:73.653, Elevation:  121 m • Select Iridium Flares for the Next 7 Days. Introduction to Engineering Electronics K. A. Connor

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15. Iridium Flares • What will you see? • Look at http://www.kevision.com/iridium.mov Introduction to Engineering Electronics K. A. Connor

16. Your Future: Life Long Learning • Find some technical hobbies or interests that help put your education in context. • Attend some lectures – Watch particularly for the Vollmer Fries Lectures. • Ask questions of faculty and staff – you may never be so close to so much information as you are now. • Make good use of services. Introduction to Engineering Electronics K. A. Connor

17. Career Development Center • Through Pathways, students may request a match with a Rensselaer alumni for a short, informational visit at their place of employment or, when in-person visits are not possible, contact with alumni mentors by telephone or e-mail is encouraged. Don’t Forget: Introduction to Engineering Electronics K. A. Connor

18. Course Surveys • IDEA Survey – These are the standard surveys used in all courses. The information helps to compare our courses with those elsewhere and to assess the development of new ideas and new faculty. • My Survey – More specific to this class Introduction to Engineering Electronics K. A. Connor

19. Introduction to Engineering Electronics The End Best of Luck Introduction to Engineering Electronics K. A. Connor