Learn More About GPS
Once upon a time, in the very olden days, people (like your parents) used printed maps and compasses to figure out where they were going. Before that they used the stars. Today, we use the GPS that uses a network of sophisticated man-made stars (satellites) to work. If you have a GPS receiver— about $100 these days — in your car or pocket you can know exactly where you are. How much do you know about this magical technology? Do you know what the letters “GPS” stand for? Do you know how many GPS satellites there are? Do you know how to Geocache? Here are some sites about the GPS.
1. What do the letters GPS stand for?
Find out at http://www.gps.gov.
2. Who paid for the GPS system? And what year was the first GPS satellite launched?
You did. See http://www.nasm.si.edu/gps/. The US military created the GPS, funded by taxes, starting in 1978. It wasn’t until 1994 that all 24 satellites were available.
3. A GPS receiver can best be compared to which
device:
a) A car radio that only receives radio waves.
b) A cell phone that both sends and receives radio waves.
Answer: a) A car radio. Visit http://www8.garmin.com/aboutGPS/. A GPS receiver is a specialized radio wave receiver, tuned to capture 24 frequencies.
4. How many satellites must your GPS receiver “see” in
order to calculate your location?
a) 5
b) 1
c) 3
Answer (c). Answer. Visit http://www.how-gps-works.com for this and other GPS facts. (Note: contains ads.)
5. The GPS satellites each are tuned to the same very
accurate clock that costs millions of dollars. Where is this clock located?
a) The moon.
b) An igloo in Alaska.
c) An airforce base in Colorado.
Answer (c). At https://gps.afspc.af.mil/gps/, you’ll learn that the official world clock is located at The Schriever United States Air Force base in Colorado Springs
Trivia Question Time! Visit http://www8.garmin.com/aboutGPS/ to find the answers to each of the following questions. Hints are below.
6. What is the number of orbits per day for most GPS statellites?
7. What is the number of years a GPS satellite lasts?
8. What is the weight of a GPS satellite?
9. How many miles from earth are most satellites located?
10. What is the accuracy of a commercial GPS receiver, in feet?
11. How are they powered?
12. What is the maximum number of satellites your receiver can“see” at any one time?
Answers (not in correct order!)
a) 12,000
b) 30
c) 2
d) 10 years
e) by the sun!
f) 2000 lbs (the same as a small car)
g) 12. The other 12 are on the other side of the earth!
13. YouTube videos explaining how GPS works.
Visit Children’s Technology Review’s (CTR) YouTube page to see more videos that explain how GPS systems work.
