Understanding GPS: A Buyer's Guide to GPS

Understanding GPS: A Buyer's Guide to GPS
Overview
The primary function of consumer-end handheld GPS units is to pinpoint your location on the face of the earth, and display through maps your distance to a desired destination. Many people can find convenience in owning a GPS unit. One of the more gemon places where they can be used is someone's vehicle, for navigational directions. Especially for off-road traveling, where both the terrain and road may be unfamiliar to you, or where overhead direction signs are scarce. For many, it sure beats humongous car maps that never seem to fold back into their normal positions, or rolling down windows and asking for directions in a strange town.
Handheld global positioning devices can be used for a number of other reasons too. People in aviation and boating also use GPS units for finding locations. If you plan to take a fishing trip, handheld GPS units will help you while you're out in the waters.
Handheld GPS units gee with various capabilities. Most fit into the palm of your hand, and have a thick but short antenna. They all have some sort of display screen, which gee in various resolutions and are usually backlit. Some units have an internal memory from which you can access a Map Database, displaying major roads and highways, cities and other navigable details. More advanced units will even allow you to load onto your device more geprehensive street detail, via an additional Flash memory. Many GPS navigators will also provide you with additional information like distance, bearing, speed, time to go, elevations and more. All units work on a rechargeable battery.
To pinpoint your position on the earth, and your distance from your desired destination, all GPS units use some type of channel tracking system. The more satellites needed or used to track your location, the more accurate the reading. Average handheld units will track using 3 satellites, while higher end units can track using up to 12 satellites, and can usually track very well even in the toughest weather conditions.
Storing Locations
One of the major advantages to GPS units is that they have the ability to store specific locations or landmarks, so that they are always remembered. Most units can store hundreds of locations, which are sometimes referred to as "waypoints", including routes and legs or branches off these routes.
Some GPS units may have a slot for optional software modules that already have pre-programmed landmarks and maps of particular regions. When this is possible, it may prove to be extremely beneficial when exploring unfamiliar areas in foreign places.
How They Work
Your GPS receiver requires signals from at least three satellites to determine your unique position on earth. With a fourth signal your altitude can also be determined. Receiving signals from more than four different satellites, the position of the GPS receiver can more accurately be determined. Cheaper models can track with only three satellites, while high-priced units can track with up to 12.
Longitude