GPS Units Buyer’s Guide
Global Positioning System (GPS) units are used to determine the accurate trip distance and route of travel. When a user enters the destination location into the GPS unit, it communicates with a network of satellites to determine the current location of the GPS unit using a method called trilateration. Once this data has been received, the GPS unit software will calculate the best route and distance to destination.
Although GPS can be used for global mapping and tracking, this expert guide will explain the different types of GPS navigation units and the features you can expect from GPS units within the different price ranges.
Available types of GPS units
There are four main types of GPS navigation systems: car navigation units which are installed in motor vehicles; portable navigation systems which are handheld and can be used anywhere; marine GPS which are designed specifically for mariners and PDA/GPS hybrids which are multifunctional.
The following specifications are important to consider during the GPS navigation unit review and selection process.
- • Accuracy and reliability
Accuracy and reliability is dependant on the chipset the GPS unit uses. The rule of thumb is to select a model that utilizes the latest chipset, such as SiRF Star III, which work better in built-up areas.
- • Speed of calculation
Some of the cheaper models can be incredibly slow to calculate your route once you have entered your destination. Even when you are on route there may be a long lag during which the unit is recalculating your position. To avoid unnecessary frustrations, check that your GPS unit has a Time to Fix (TTF) of less than 30 seconds.
- • Screen size
Screen size is very important, especially if you are looking at buying an in-car navigation system. Make sure that you will be able to see the directions on the screen while driving without having to divert your eyes from the road for too long.
- • Pre-loaded maps
Not all GPS navigation systems come pre-loaded with maps which means you will have to buy country-specific maps to upload into the unit. Even if your GPS unit is pre-loaded with your country map and you intend using the unit abroad, you may have to buy additional maps.
- • Battery
Check the type of battery and the expected battery life of portable GPS navigation units. A good quality GPS unit should offer a battery life of 4 hours or more.
- • Optional Features
There are a variety of different features offered with the different makes and models of GPS units, including hands-free speakers; weather reports and local area information. Not all optional features will be necessary, depending on your GPS requirements and it is important to keep in mind that the more features a GPS unit has; the costlier it is likely to be.
Entry level budget
It is possible to get a basic, portable GPS unit for under $100. They offer few optional features but if all you require is a device that will get you from A to B then they are adequate.
The Mio DigiWalker C220 can be bought for around $75, is compact and easy to use. It comes pre-loaded with maps; has a 3.5 inch color touchscreen; provides voice guidance and is SD compatible. This reasonably priced GPS unit has received an impressive average expert review rating of 70%. To read these reviews, refer to www.testseek.com.
Entry level GPS navigation units offer good value for money but there are some compromises. Many of the cheaper have smaller screens, around 3.5 inches, which can be difficult to view in harsh sunlight. Some of them have noticeable TTF delays and complete accuracy cannot be guaranteed.
If you are willing to spend between $100 and $200, you will get many more features with the GPS unit such as traffic data and alternative routes.
The Garmin StreetPilot C550 is an incredibly easy to use GPS navigation system which has the ability to receive traffic information. This compact, 3.5 inch touchscreen unit comes with pre-loaded maps; allows the user to adjust the screen brightness and is Bluetooth-enabled. With an overall expert review rating of 84%, this unit is well priced at around $160.
Some of the more expensive GPS units can guarantee superior accuracy, along with Bluetooth hands-free; shorter TTF times and onboard traffic information and re-routing suggestions.
The Tom Tom Go 730 Traffic is very expensive but incredibly accurate. This 4.3 inch touchscreen GPS unit not only offers traffic information but it even provides traffic lane guidance. This means that it can tell you which lane you should be in when you approach roundabouts or highway off-ramps. It is also easy to use and as it uses a SiRF Star III chipset, its signal strength is always strong. Priced at around $350, this GPS unit has received an excellent expert review rating of 96%. To view these reviews, go to www.testseek.com.
There are plenty of GPS units on the market, before buying one you should ensure that it has all the features you require and that it is accurate with a good TTF time.
Disclaimer: This guide was written in late 2008 and the specific product recommendations may be outdated. However the basic discussions in this buyer's guide may still be of great value.
Written by; TestSeek staff