Motorola ML910 - Manual (Page 69)

Operating Your Computer 2-25
Using GPS (Optional)
Navigation and positioning are crucial to many activities and yet the process has always
been quite cumbersome. With GPS technology, you can now figure out where you are
and where you are going.
Global Positioning System (GPS) is a worldwide radio-navigation system formed from a
constellation of 24 satellites and their ground stations. GPS uses these "man-made
stars" as reference points to calculate positions accurate to a matter of meters. In a
sense, it is like giving every square meter on the planet a unique address.
Five broad categories of GPS application:
z
Location – determining a basic position
z
Navigation – getting from one location to another
z
Tracking – monitoring the movement of people and things
z
Mapping – creating maps of the world
z
Timing – bringing precise timing to the world
NOTE:
1. The basis of GPS is "triangulation" from satellites.
2. To "triangulate," a GPS receiver measures distance using the travel time of radio signals.
3. To measure travel time, GPS needs very accurate timing.
4. Along with distance, you need to know exactly where the satellites are in space.
5. Finally, you must allow for any delays the signal experiences as it travels through the
atmosphere.