Buying a GPS…

by techtiptom

Originally posted on on 12/03/2009:

GPS navigation is one of the miracles of modern technology – some people liken its impact on traveling to the emergence of Google’s search technology on the internet.

The way it works is incredible: it picks up signals being constantly pinged to earth from 30 global positioning satellites orbiting the Earth and works out based on the fractional delay in signals from different satellites exactly where you must be. The satellites were launched into the space by the United States for military purposes in 1973, but have since been opened up for civilian use.

A GPS navigator matches your location to an electronic map provided by a mapping provider such as Sensis (a division of Telstra) or Navteq (a division of Nokia). It then evaluates thousands of different routes to get you to your destination and picks the fastest one.

From that point, it gives you live turn-by-turn spoken navigation, so you can keep your eyes on the road and get to your destination without a stressed moment ever again.

The most recent GPS navigators add helpful features like speed and red-light camera warnings; can help you find businesses in a specific area (e.g. “take me to the nearest gas station”, or “take me to a florist on the way to my destination”.).

The first time you turn a GPS navigator on (and each time you turn it on if it hasn’t been used for a while) it must first scan all the satellite signals and acquire a lock. This can take two or three minutes, however each subsequent time you turn it on, it will lock on to the signals within just a few seconds. Most navigator brands allow you to connect your navigator to a computer to periodically download satellite orbit information to allow it to acquire a lock more quickly.

Map updates are an area to be aware of. It’s far more important on an electronic navigator to have an up-to-date map than the old days of street directories. It can be significantly dangerous if your navigator suddenly instructs you to turn right while you’re traveling over a newly built bridge, or tells you to turn into a street that used to be two-way but has since become one way.

Some lesser known budget brands of navigator may not provide easy map update options, whereas the more established brands will.

Do you need Bluetooth?

Some navigators have Bluetooth built in, which allows you to connect your Bluetooth-compatible mobile phone and use the navigator’s speaker as a handsfree telephony device.

Traffic congestion alerts

The very latest navigators can access traffic congestion broadcasts so they can avoid congested roads when plotting the fastest route. This is called “Transportation Management System” (TMS) capability and requires both a paid subscription to the TMS service as well as a GPS navigator capable of receiving the signals. TMS signals are broadcast over FM frequencies, so your GPS navigator needs to have an FM antenna for the TMS system in addition to its inbuilt GPS antenna.

Screen size

Some navigators boast increased screen size over basic models. You might wonder why this is worth paying for when most of the time you won’t be looking at the onscreen map, but will instead be following the spoken instructions.

The answer is that the bigger the screen, the bigger the keys on the onscreen keyboard. When tapping in a destination using the touchscreen, it can often be quite fiddly to hit the right keys. A larger keyboard makes a GPS navigator considerably more enjoyable to use because you’ll be able to type destination addresses in with ease.

Inbuilt camera

One feature of GPS navigators that seems to polarize people is an inbuilt camera so you can save your destinations along with a picture of the scene upon arrival. This allows you to then browse destinations later by photo rather than just name. Some people swear by the usefulness of the feature (especially since you can download other users’ pictures and install collections of scenic places in particular regions etc for special holidays) while other people say it’s a gimmick that adds nothing to your navigation. I’ll let you decide!

Special types of GPS

In-car GPS isn’t the only place GPS technology is being applied. If you’re a cyclist, avid walker, or a fisherman (fisherperson?), you’ll find there are special GPSes designed just for you.

For example, the TomTom Rider GPS for bikes is weather proof, has Bluetooth capability that can link to a headset in your helmet, is encased in rubber for durability against knocks, has an ultra-bright screen for use in direct sunlight and so on.

GPS units for walkers have comprehensive walking track databases, place extra emphasis on compass and altitude information, may be able to record your walking routes and then plot them onto maps for you later, and may connect to a heart rate monitor.

Marine GPS units have sea-floor depth maps, can interface with sonar and weather units, and can plot routes that avoid obstacles, shallow water, buoys and other obstructions.

Don’t forget to check the accessories

Most dedicated GPS navigators come with decent windscreen mounts and a car charger, but you may want to buy an additional set of them so you can use the navigator in a second car without having to unplug and pack everything up.