Hottest Electronic GadgetsGadget Gear Guide

To see the imapct on your car insurance rates have a look at car insurance coverage quote. Each and every one of us must have already heard about GPS receivers. We hear about them whenever a new luxury vehicle is launched. We also often hear about them from our techie and adventurous friends. But while the term is so common, many of us really know nothing about the thing. So what really is a GPS receiver?

A GPS receiver, or simply GPS as other people would call it, is an electronic device that can determine one’s precise location on earth. Calling the device simply GPS, however, is incorrect because the receiver is but a single and small part of the GPS, which is a very large navigation system.

GPS in Brief

The abbreviation GPS stands for Global Positioning System. It is a very large navigation system that was developed and implemented by the United States’ Department of Defense (DOD). The system is composed of a network of 27 satellites, different ground stations around the world, and GPS receivers. 24 out of the 27 satellites in the GPS are active and they continuously send radio signals. These signals, in turn, are used by GPS receiver to determine their geographical location.

How GPS Receivers Work

The primary function of a GPS receiver is to calculate its actual location on earth using the signals it intercepts from GPS satellites. To do this, the GPS receiver must be able to locate three or more GPS satellites from where it will intercept signals. After intercepting the signals, it will use the basic principle of mathematics called trilateration or triangulation to compute its actual position.

Now, before any triangulation calculation can be implemented, the GPS receiver must first know 2 things:

- the position of at least 3 satellites, and
- the distance of each satellite to the receiver.

A GPS receiver can determine the location of at least three GPS satellites by decoding the signals it receives. The signals transmitted by GPS satellites are radio signals that contain three different bits of information: a pseudorandom code, ephemeris data, and almanac data. From the three, it is the ephemeris data that actually gives the actual position of the satellite transmitting the signal.

For the distance of a GPS satellite from the GPS receiver, the receiver simply measures the signal’s speed, or the time delay from the transmission of the signal to its reception. From this speed or time difference, it can determine the satellite’s distance.

With information about the location of at least three or four satellites and their individual distances, and by using the principle of triangulation, the GPS can calculate its actual position in terms of latitude, longitude, and altitude.

Accuracy of GPS Receivers

In general, GPS receivers are accurate to within 20 meters of radius. With the use of supplemental technologies, however, modern GPS receivers can increase this accuracy level. GPS receivers using multiple parallel channels, for example, can increase the accuracy level to 15 meters. More complex systems like WAAS (Wide Area Augmentation System) and DGPS (Differential GPS) can even reduce this range up to less than 3 meters.

Despite the use of these supplemental technologies, there are still a lot of factors that can cause even the best GPS receiver to broadcast inaccurate locations. Among these factors are:

- Radio signal delay as it passes through the ionosphere and troposphere
- Bouncing of signal as it hits an object (signal multipath)
- Inaccuracy of GPS receiver clock
- Ephemeris errors, or inaccuracy of the satellite’s reported location
- Number of satellites visible
- Poor positioning of satellites (satellites are in a linear position or in a tight grouping)

Although some of the GPS errors that these factors cause can be remedied by the software that comes along with the GPS receiver, others simply can’t. Nonetheless, GPS receiver manufacturers are continuously developing technologies to correct these inaccuracies.

For more information regarding insurance savings look at http://www.quick-online-insurance-quote.com and http://www.quick-online-insurance-quote.com/blog/.

No related posts.

Related posts brought to you by Yet Another Related Posts Plugin.