Garmin StreetPilot 2620 Owner's Manual

Contents

Garmin StreetPilot 2620 Owner's Manual Manual pdf 64 page image

Reference56GPS Info PageUnderstanding the GPS Information PageWhat is GPS?The Global Positioning System (GPS) is a satellite-based navigation system made up of a network of24 satellites placed into orbit by the U.S. Department of Defense. GPS was originally intended for militaryapplications, but the government made the system available for civilian use in the 1980s. GPS works inany weather condition, anywhere in the world, 24 hours a day. There are no subscription fees or setupcharges to use GPS.GPS satellites circle the earth twice a day in a very precise orbit and transmit signal information toEarth. The GPS receiver that is located in your StreetPilot takes this information and uses triangulation tocalculate your exact location. Essentially, the GPS receiver compares the time a signal was transmitted by asatellite with the time it was received. The time difference tells the GPS receiver how far away the satelliteis. Now, with distance measurements from a few more satellites, the receiver can determine your positionand display it on the StreetPilot’s Map page.A GPS receiver must be locked on to the signal of at least three satellites to calculate a 2D position (lati-tude and longitude) and track movement. With four or more satellites in view, the receiver can determineyour 3D position (latitude, longitude and altitude). Once your position has been determined, the GPS unitcan calculate other information, such as speed, bearing, track, trip distance, distance to destination, sunriseand sunset, time, and more.The GPS Information PageThe GPS Information page provides a visual reference of GPS receiver functions, including currentsatellite coverage, receiver status, and position accuracy. To access this page, press the StreetPilot MENUkey; a Menu page will appear. From the Menu page, select the Info icon, and an Info page will appear. Touchthe GPS Info icon and the GPS Information page will appear.GPS satellites are positioned throughout the sky. As soon as you turn on your StreetPilot, it attempts toacquire satellite reception. From the sky view area on the GPS Information page, you can see which satel-lites are currently in your area; each satellite has its own number (from 1-31).A hollow bar (such as satellite numbers 6, 15, and 17)indicates the StreetPilot has found the satellite(s) andis collecting data. Note how the StreetPilot has not yetfound satellites 9, 10, 16, 22, and 23.Solid green bars indicate the StreetPilot has collectedthe necessary information and that satellites 18 and 21are ready for use.