There are two types of GPS systems:
- Interactive: These recognize the roads and tracks you are traveling on. Google Maps is an example of this system and can show nearly all of the smaller tracks. The problem with this system is when you zoom out to get an overview of where you are, the smaller tracks disappear from the display. This makes it difficult if you are planning a trip or you have to choose a new route. You should always carry a paper map to help with planning and in case the GPS fails. These systems are possibly more suited to road trips and outback Australia than they are to the High Country. Other examples of these systems are Hema Explorer, ExploreOz Traveller and Back Country Navigator.
- Non-interactive: This displays a picture of a scanned paper map and has no interaction with the picture in the display. The GPS is able to show your location on the map. An example of this system is OziExplorer. If you have the same physical paper map as that displayed in the GPS then it is much easier to work with when planning trips.
External GPS Receiver: If you are running a GPS app on a tablet then you need to make sure that the tablet has a real GPS receiver. Some tablets advertise “GPS” which is a satellite system but in fact they are getting their location from mobile phone towers. This is useless if you don’t have mobile reception. You can buy an external GPS Receiver which connects to your tablet via Bluetooth or USB cable. Alternatively, you may be able to connect to the GPS receiver in your phone but first make sure that it has a real GPS receiver.
Dedicated GPS unit vs app: Both VMS and Hema offer their systems in a dedicated GPS unit or you can purchase their app and download it to your own device. The advantage of using your own device is that you can purchase something with a bit more processing power and you can also use it with other apps such as a battery monitoring system or WikiCamps.
Screen Size: The dedicated GPS units usually have a 7 inch screen which is ample. An 8 inch screen tablet (9″ overall) also fits nicely on a dash but you will need to check your own dashboard layout. Make sure it does not obstruct your visibility of the road.