What It Is and How It Works - For those who are unfamiliar with the term, GPS stands for Global Positioning System. It's a way of locating a receiver in three dimensional space anywhere on the Earth, and even in orbit about it, and it's probably one of the most important inventions of the 20th century. GPS can be used in so many varied ways that new technologies are constantly being developed and improved in order to take advantage of it. Now why is GPS so important and useful? First, we have to understand how it works.

In order for GPS to work, a network of satellites was placed into orbit around planet Earth. These satellites each broadcast a specific signal, which is received by inexpensive aerials and passed on to GPS devices where it is then decoded and used by dedicated software. The information is specific enough that the GPS software can identify the satellite, it's location in space, and calculate the time that the signal took to travel from the satellite to the GPS receiver. Using different signals from different satellites, the GPS software is able to calculate the position of the receiver.

Mapping It Out - Knowing where the device is in space is one thing, but it is fairly useless information without something to compare it with. The mapping part of any GPS software is very important; it is how GPS works our possible routes, and allows the user to plan trips in advance. In fact, it is often the mapping data which elevates the price of the GPS solution. This should be updated regularly and frequently in order to be accurate.

There are several kinds of maps, and each is intended for different users with different needs. Road users need maps containing accurate data about the road systems in their particular region, but they won't need data about the lay of the land. Hikers, however, might require a more detailed map about the local terrain, water spots, and tracks or trails, but they won't need extensive information about the road systems. On the other hand, sailors will need specific data about the sea bed, navigable channels, and other related information that will allow them to navigate safely.

And what about fishermen? They also use marine GPS to keep track of the movements of fish in real time and to predict where they'll be the next day. The advent of GPS fixing has also meant that co-operative fishing has become much easier, where several boats relay their locations to each other while they locate the best fishing waters. Special kinds of marine GPS, known as fishfinders, also combine several functions in one to help fishermen.

Get Started with GPS - Consumers can avail of several GPS devices that are specifically designed for a variety of uses and functions. In-car systems have advanced features like voice guidance, dynamic route calculations, and even upgrading your maps from a CD-ROM. Rugged handheld GPS devices, like those from Garmin and Magellan, have a map inside and are usually used for outdoor activities. They generally do not have any road information, and leave the users to find their own way from A to B.

A more recent solution has appeared on the market which uses the power of a PDA to run the actual GPS software. A GPS receiver can be easily attached to these devices, so these tend to be the cheapest, easiest to use and most flexible solutions. Bluetooth technology has also started to make use of GPS, by having several receivers with Bluetooth capabilities, and a single PDA.