Principles Of Operation: Notes

WARNING: This page is about a different car, the 2012 Land Rover Range Rover Sport and 2011 Land Rover Range Rover Sport. However, it is still accessible from the selected car via links, so may be relevant.

The system used to calculate the current position of the vehicle is called the global positioning system (GPS). Satellites transmit radio signals to provide information about the satellite's position, for example the latitude, longitude, altitude, almanac data and an accurate time signal generated by an on-board atomic clock. Each satellite contains four atomic clocks.

The vehicle needs to receive data from at least four different satellites to give a three dimensional fix on its current position.

As the vehicle moves, this information is continually being updated. The TSD determines which satellites are 'visible' to the system and their current position and relationship to each other. Using this information the TSD can account for positional deviations of the satellites and compensate to enhance the accuracy of the navigation system.

The GPS signal is also known as the PPS (precision positioning signal).

PPS predictable accuracy is:

22 meters horizontal accuracy
27.7 meters vertical accuracy
200 nanoseconds time accuracy.

The navigation system receives GPS information via the GPS antenna. The GPS signals are used by the TSD to calculate the vehicles position. Once the driver has input a desired destination the TSD can calculate a route, based on the driver's pre-determined preferences or the default settings in the TSD.

The navigation system is accessed by pressing the navigation switch on the integrated control panel.

Navigation is initiated by the driver entering a destination. This can be achieved by:

Entering in an address using the touch screen display.
Entering a post code.
Choosing a previous destination.
Choosing a point of interest from the hard drive database.
Choosing the home location.
Choosing a memory stored location.

The driver is then guided to the destination by a scrolling map display and voice guidance. The display can be varied by scale and display type.

In addition to the navigation system there are two market dependant systems that supply extra information to the navigation system and the driver. These are:

TMC (traffic message channel - Europe only.
VICS (vehicle information and communication system) - Japan only.