Today there is a huge selection of GPS systems catering for the needs of different applications and users. We would like to classify these systems under following main categories.
The basic units are just the plain old receiver with minimal set of features. A basic unit can be bought for around 100 dollars.
These simple devices have the basic functionality of reporting the location in terms of latitude and longitude. They may also have a base map (a very high level map that contains major highways and few Points of Interests) of a region. Basic units have limited processor and memory capacity.
These units are ideal for a person with low budget whom would like to use GPS for basic navigation, educational activities and fun.
Sports / Training Units
Sports enthusiast or training athletes will find wearable units very useful. These units can be worn in the wrist like watches.
They have many integrate features such as heart rate monitors, lap/racing timers, calorie count monitors, and virtual partner software that allows you to set your workout target and objectives.
Many wearable units come with associated PC software that can be used to plan and analyse your workout information.
Portable GPS units can be used in car or by a pedestrian.
Lower end portable models may have small screen sizes and little memory capacity. Due to their limited memory capacity they can only store maps of a specific region. It may not be possible to store the whole map of a country like the United States. The maps on lower end portable units are usually stored in SD Cards, CD ROMs or in the system’s built memory.
Higher end potable units have larger screens and large memory storage capacity. They typically use a hard drive or DVD disk to store the map software. Most of the high end portable units have other cool integrated features such a MP3 playback capability, xm satellite radio services, picture viewers, audio books and blue tooth integration.
Car GPS systems
Car GPS systems come in two flavours
1. Portable Add-on units
Many people now a days use a portable unit (see above) in automobiles. Most of the portable units come with accessories that allow the user to use them in a vehicle. These accessories include suction cup to attach the unit to the windshield, car power adapter, battery charges, external antennas and etc.
2. In-dash units
These are top of the range systems that provide a wide selection of features that nicely and tidily integrate with your car electronics. In-dash units are more expensive. They have to be permanently mounted in the car. This means you cannot move unit if you happen to take another vehicle for your next road trip.
In-dash units give a professional look and feel. They have no clutter (like power adapter wires, suction cup etc). One of the main disadvantages of in-dash units is that they are permanently fixed to the car and might be prone to theft.
Double DIN systems
A Double DIN system occupies two bays in your car dash. Since they are fitted inside the bay, they do not project out and less noticeable from the outside. This might prevent the system from being stolen when the car is unattended.
PDA based Systems
A PDA which stands for Personal Data Assistant is a hand held device that has trimmed down features of a Personal Computer.
A PDA that uses the Palm OS software is usually known as a Palm Computer, while PDA the uses the Microsoft mobile operating system is called a Pocket PC.
Buying a PDA based GPS system has the added advantages of using the unit as a handled computer for general productivity and entertainment as well a using it as a GPS navigation tool.
If you already own a PDA, you can buy a GPS add on module, thus saving your initial investment in your PDA.
Laptop based Systems
Laptop based GPS systems are relatively cheap compared with other standalone GPS units. In these systems the map and software are loaded into the laptop hard drive. The only accessory that you need is a simple receiver that can connect to your computer (via USB or serial ports).
The mapping software loaded into the computer will be able to perform the navigation. Most laptop systems come bundled with a GPS receiver. Compared with other GPS systems, a laptop system is bulkier.
But the advantage is that you are leveraging the laptop CPU power, memory and hard disk capacity for your navigation needs.