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A GPS automotive navigation system is a satellite navigation system designed for use in automobiles and it acquires position data to locate the user on a road the unit's map database. GPS (Global Positioning System) is a navigational system designed and operated by the U. S. Department of Defense (DOD). Coded satellite signals from three or more GPS satellites are processed by your vehicle's navigation computer every second, which then calculates the vehicle's velocity and geographical location. The map database displays the current location, finds destinations, road construction and points-of-interest. Vehicle navigation systems provide visual and/or audio turn-by-turn instructions to guide the driver to the desired location. GPS units are available for cars, motorcycles, boats and airplanes. You may also purchase a handheld unit to take hiking or mount on the handlebars of your bicycle. (Handheld units also work in cars and boats.)
Under typical conditions, a GPS can calculate your position accurately within about 15 meters. Newer GPS receivers can take advantage of WAAS (Wide Area Augmentation System), a series of ground-based signals which improves GPS accuracy to within 3 to 5 meters. A GPS must have a direct line of site with satellites above. Dense vegetation and tall buildings can block the signal.
SiRF Star III Chipset is found on many of today’s GPS navigation systems and represents a significant advance in GPS technology. The chips allow a GPS to get its satellite fix (i.e., figure out its location) much faster than before. The SiRF chips are much more sensitive than other chips, allowing the SiRF-equipped GPS a much better ability to lock onto weak satellite signals and it accomplishes all of this while using much less power, providing longer battery life.
Types of In-Car GPS Navigation Systems
In-dash GPS navigation systems typically consist of a car stereo with a built in monitor, a connection box that contains A/V inputs and outputs (usually mounted behind the dash or under a front seat), and an external GPS antenna.
Remote mount GPS navigation systems are made up of a self-contained GPS receiver that must be connected to a compatible in-dash stereo.
Plug-and-Play GPS receivers are ideal for anyone who wants the convenience of an in car navigation without a permanent installation. These portable units attach quickly to the windshield or dash and use the cigarette lighter adapter to for power, which makes it easy to transfer them from vehicle to vehicle.
What should I look for in a GPS/Navigation system?
If you plan to use a GPS receiver primarily in your car, look for either an in-dash, remote-mount, or plug-and-play system, as these include special features designed specifically for use while operating a vehicle, such as voice prompts, large, bright screens, and built-in speakers.
Accuracy, speed, and ease of use
Accuracy, speed, and ease of use are things you should look for while reading reviews of various navigation systems. Pay particular attention to the opinions regarding navigation accuracy, the speed of route calculation and recalculation, and the ease of working with the screen's control interface.
Screen size
The bigger the better. Most are either 6-1/2 or 7 inches (measured diagonally). Larger screens can also be helpful if the ideal mounting location is far enough away to require squinting. Large displays may also offer more control functions on a specific display screen than a smaller one. An increasing number of GPS models are being offered with a wide screen option.
Internal memory
Internal memory lets you play music while you are navigating. The memory saves the route you've programmed, so you can remove the map disc and use the slot for your CDs or DVDs. A bigger internal memory means that more map information can be saved at a time. This is particularly helpful in route recalculation. With a large internal memory, you won't have to re-insert the map disc if the system needs to reroute you because of a missed turn, construction, traffic jams, or other problems.
Points of interest
Points of interest help you find various locations including restaurants, hotels, gas stations, and ATMs. Many systems let you program several stops along the way to your destination.
Real-time traffic data
Some systems are compatible with real-time traffic services. For a monthly fee, you can receive real-time traffic information, including traffic jams and construction. This service is also useful for people with long commutes to and from work.
Touchscreen
Touchscreen controls you to tap the screen in the appropriate spot to enter a command. This saves you time and is found in most in-dash systems.
Voice-Guided Turns
Voice-Guided Turns provides spoken directions to guide you along your way so you can keep your eyes on the road, an important safety feature. The unit may make up to three announcements before a turn, giving you plenty of time to prepare, and without ever taking your eyes off the road ahead.
Text-to-Speech
Text-to-Speech capabilities are available in higher end in-vehicle GPS Navigation Systems and will “read” street names to you while providing spoken turn-by-turn directions. Instead of “In 1 mile, turn left” you’ll hear, “In 1 mile, turn leftt on Broad Street”.
Off-road Use
In-vehicle GPS Navigation Systems are designed to guide you along the roadways. If you steer off-road, the database used by your GPS may not include the dirt road you’re using. Fortunately, the GPS will still keep track of where you are relative to the roads and points of interest it does know. Some units allow you to access latitude and longitude information, helpful if you need to navigate toward specific coordinates. There are only a small number of GPS units that can provide both on-road and off-road capabilities, but this number should grow over the next few years as demand increases.
Bluetooth
Bluetooth is a wireless technology that allows mobile phones, computers, GPS units, personal digital assistants (PDAs), and many other devices to be easily interconnected using a short-range wireless connection. Some GPS units can double as a speakerphone, connecting wirelessly to your Bluetooth-enabled mobile phone. This can provide enhanced safety and convenience by automatically calling a hotel or restaurant at the push of a button.
MP3 Audio Player/Audiobook Player
MP3 Audio Player/Audiobook Player is a popular feature on in-vehicle GPS units is the ability to play MP3 or other audio files through your GPS. Some units also include a special player for audiobooks.
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