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How Does A Garmin GPS System Work?

Garmin GPS (Global Positioning System) receivers use GPS satellites which orbit around the Earth. Time orbital time period of these satellites is 12 hours which means they circle around the Earth two times each day and transmit back the signals. In total there are 24 GPS satellites that were in Earth’s orbit in 2008.

These orbits are arranged in such a fashion that there are at least 4 satellites visible to the GPS receivers at a time. Garmin GPS receivers receive the satellite signals and use them to triangulate the location of the user through trilateration.

When you know that you are at a distance of 15 miles from a satellite A, you can be somewhere in a sphere of radius 15 miles. But, if find yourself at a distance of 10 miles from a satellite B, you now will be in a second sphere which must be converging the sphere of satellite A.

To triangulate further, you can add a third sphere which shows that you are at a distance of 10 miles from the satellite C. Now, you know that you are somewhere in that small region where these three spheres converge.

Trilateration

GPS Receiver

When the Garmin GPS systems receive the signals from the satellites, they compare the timing when the signal was sent with the time when the GPS receives it (each satellite is equipped with an atomic clock). This comparison is done in order to calculate the current distance of the satellite.

The GPS receiver is required to pick up the signal from at least 3 satellites in order to accurately calculate its latitude and longitude. Moreover, to calculate a 3D altitude location, the GPS system must be locked into the signal of a fourth satellite.

Once the GPS receiver is able to find out the location of the user, it can easily calculate the speed at which the user is traveling by updating its position constantly with the satellites and hence, calculating the total distance traveled by the user along with the time of travel.

If the user enters a destination location, the GPS receiver calculates the distance of the destination from the current user’s location and also the time to the destination depending on the current speed of the user. Also, for all users, Garmin provides support which helps them to sort any further difficulty with the device.

Since the receivers like Garmin Nuvi come pre-programmed with a database of sunset and sunrise times, they can also tell the users the exact time of sunset and sunrise in their current location.      

How Accurate Can Be A Garmin GPS?

Most of the Garmin GPS systems have a high accuracy as they are featured with a parallel multi-channel design, which allows them to lock into a satellite signal when switched on and enables them to maintain the lock even if the system is surrounded by tall trees or buildings.

Usually, Garmin GPS devices are perfectly accurate within an area of 15 meters of a radius. However, Garmin GPS featured with Wide Area Augmentation Systems are accurate only for less than 3 meters. Furthermore, the Differential GPS, that corrects the GPS signals, is accurate up to 3 to 5 meters.

Certain weather conditions may cause inaccuracies in a GPS receiver.  These may include troposphere and ionosphere delays that are caused by a lagging signal as the satellite goes through the atmosphere. A GPS system is equipped with a built-in measure in order to correct this time-delay error.

The accuracy can also be affected by the number of satellites visible. For instance, an electronic interference and dense foliage may cause the GPS system to see lesser satellites.

Call Garmin Customer Service 1-855-403-8088