1. ELECTROMAGNETIC RADIATION And Its SPECTRUM

2. What is Electromagnetic Spectrum? • The electromagnetic spectrum is a collection of electromagnetic waves arranged according to frequency and wavelength.

3. How EMR’s are formed Electromagnetic waves are formed when an electric field (which is shown in blue arrows) couples with a magnetic field (which is shown in red arrows).

4. WHAT ARE WAVES? WHAT IS WAVELENGTH? WAVES: Waves are a series of crests and troughs moving past a given reference point. WAVELENGTH: It is the distance from one point on a wave to the corresponding point on the next consecutive wave.

5. WHAT AREELECTROMAGNETICWAVES? Static electricity can make your hair stand on end. Magnets can attract certain metals. Radio waves, TV waves and microwaves are all types of electromagnetic waves. However, they differ in wavelength and energy.

6. Scientific Notation POWER DECIMAL PREFIX PHONIC SYMBOL OF TEN EQUIVALENT 10 12 1 000 000 000 000 tera ter'a T 10 9 1 000 000 000 giga gi'ga G 10 6 1 000 000 mega meg'a M 10 3 1 000 kilo kil'o k

7. COMPARISON OF WAVE LENGTHS WITH IN THE ELECTROMAGNETIC SPECTRUM FREQUENCY = the number of cycles per second HERTZ = the unit attached to frequency

8. EMR SPECTRUM CHARACTERISTICS Radio Micro Infra Visible UV X-rays Gamma Waves Waves Red Light Light Rays ---- Frequency Wavelength --- Energy

10. Common Hertz Relationships HERTZ TYPE ____________________________________________________________________________________________________ approximately 60 Electrical power _______________________________________________________________________________ 5 - 20000 (20 k) audio frequencies - human _______________________________________________________________________________ 10 k - 30 G radio frequencies _______________________________________________________________________________ 540 k -1600 k Amplitude Modulation (AM) _______________________________________________________________________________ 88 M -108 M Frequency Modulation (FM) ________________________________________________________________________________ 30 M - 300 M VHF - TV (very high frequency) ________________________________________________________________________________ 54 M - 890 M CATV (Cable Antenna Television) ________________________________________________________________________________ 300 M - 3000 M (3 G) UHF - TV (ultra high frequency) ________________________________________________________________________________ 3 G - 30 microwave (super high frequency) ________________________________________________________________________________

11. FEDERAL COMMUNICATIONSCOMMISSION Government Agency that Monitors and Controls Mass Communication Industries

12. WHY USE MICROWAVES FOR COMMUNICATION? Microwaves are good for transmitting information because their energy can penetrate fog, light rain and snow, clouds and smoke.

13. SATELLITE ORBITS Three basic kinds of orbits: 1)GEOSYNCHRONOUS - also called Geostationary or Synchronous) 2)Asynchronous - used by space shuttle - very low altitude (400 miles) - pass over at different times of the day 3)Polar - low altitude - passes over the earth’s poles on each revolution

15. References • Date obtained: September 21, 2005 http://imagers.gsfc.nasa.gov/ems/ems.html • Date obtained: September 21, 2005 http://imagine.gsfc.nasa.gov/docs/science/know_l1/emspectrum.html