The Global Positions System or simply GPS system is a space-based satellite navigation system that provides location and time information in different weather conditions, anywhere on Earth. All that is required is an unobstructed line of sight to four or more GPS satellites. Maintained by the United States, these GPS satellites circle the earth twice each day on a defined orbit and transmit signal information to earth.
How it Works?
Garmin GPS receivers take this information and use triangulation to calculate the user’s exact location. Ideally, a GPS receiver compares the time at which a signal was transmitted by a satellite with the time it was originally received. This time different tells the receiver how far away the satellite is. With the accurate distance measurements from few more satellites, the GPS receiver is able to provide the Garmin GPS system user his or her exact location and displays on the unit or map.
1. The first GPS satellite was launched in 1978
2. A flock of 24 satellites was achieved by 1994
3. Each satellite is built to last about 10 years.
4. Replacements are constantly built and launched in space
5. The approximate weight of a GPS satellite is 2,000 pounds and is 17 feet across with extended solar panels.
6. Transmitter power is only 50 watts or less
Accuracy of GPS
GPS receivers offer high accuracy. With help from their parallel multi-channel design and USB Cable Garmin, these are quick to lock onto satellites and maintain strong connections, despite dense foliage or urban settings with tall buildings.
Other devices commonly used to map out densely populated areas are topographic maps.