GPS (Global Positioning Systems) are becoming the norm these days. They help cars and ships navigate on the surface of this lovely place we call Earth. Even car rental companies are installing GPS navigation systems in their cars to remain competitive. So for those who can't seem to remember roads no matter how hard they try, this is great news. But perhaps you may be curious as to how the entire system works.



For GPS navigation to work, it has to complete 2 functions - (1) determine the location and (2) recommend directions. For the sake of simplicity, let's just consider the sat nav on a car.

A GPS receiver is a passive tool that receives information from satellites in the sky. These satellites are at precise locations, and they send information about their location to the receivers. The two vital pieces of information are time and distance.

A receiver needs the information from at least 3 satellites before it can calculate its own position. This is called triangulation. It is obvious that the accuracy of the position depends on the accuracy of the information that is transmitted by the satellites. The more precise the information, the more accurate the position.

For this reason, sat nav systems can only work when communication between the receiver and the satellites is unblocked. That means the communication has to take place outdoors. Even then, the sky should be as clear as possible. Sat nav systems are known to produce calculation errors when deployed in forested areas.

In addition, some satellites are further away than others. The further away the satellite, the more inaccurate the calculations. Errors may also be introduced when signals are reflected by tall buildings or other objects. The good news is, modern technology has managed to limit such areas to somewhere between 10 to 20 meters.

Once the location has been accurately determined, the job of the satellites has been completed. It's up to the receiver to relay important information to the driver now. And where is where product differentiation comes in. Not all receivers work in the same way. The better receivers, like the TomTom 530, has unique features that will help drivers navigate more easily.

For instance, the TomTom 530 as a unique feature known as IQ routing. IQ routing calculates the estimated time to travel from point A to point B based on realistic driving speed. Usually, the speed limit of the roads is used in such calculations. But such calculations are unrealistic because speeds are affected by road conditions. If speed limit is 70km/hr, but the realistic average speed is only 20km/hr, the TomTom 530 uses 20km/hr in its calculations. A driver may then easily see which are the fastest routes to take and make a decision easily.

On top of that, the TomTom 530 also offers advanced lane guidance using realistic graphic representations of lane junctions.

When you combine a feature rich receiver with satellite technology, the results can be surprisingly effective.