LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Land Rover >> 2000 >> Discovery >> Repair and Diagnosis >> Accessories & Equipment >> Infotainment >> Navigation System >> Description >> General
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Navigation System: Description: General

The navigation system provides audio and visual route guidance to help the driver reach a selected destination. The system is an optional fit consisting of a Traffic Pro navigation computer and antenna, manufactured by Harman/Becker Automotive Systems, which are fitted in place of the In Car Entertainment (ICE) head unit and antenna. Compact Disc (CD) and radio functions are incorporated into the navigation computer.

The navigation system allows the driver to choose between the shortest and fastest routes between the vehicle's current position and a selected destination, and to select a stopover point in the journey and a route that avoids motorways, ferries and toll roads. Directions to Points Of Interest (POI) e.g. airports, hospitals, petrol stations etc, either local, national or in another country, can also be selected. A traffic jam function enables the driver to request diversion instructions, around an obstructed part of the selected route, during the journey. A Traffic Management Control (TMC) function, currently only available in some European countries, monitors traffic broadcasts and automatically selects an alternative route during the journey if the original route is effected by a traffic jam, accident or road works etc.

The position of the vehicle is determined by the navigation computer using a combination of vehicle sensor inputs and radio signals from the 24 Global Positioning System (GPS) satellites orbiting the earth. The position of the vehicle is then plotted on a digitized map, loaded into the navigation computer from a CD-ROM, to determine the journey route and provide the route guidance.

The GPS satellite signals are used for initial determination of the vehicle's position and periodic position updates. The vehicle sensor inputs are used to monitor the vehicle's direction of travel and distance travelled between position updates from the GPS satellite signals. The vehicle sensor inputs consist of:

The signal from each GPS satellite contains information about satellite position, almanac data and time (almanac data is the current status of the satellite). Signals from between five and 11 of the GPS satellites can be received at a given point on the earth's surface at any one time. The number and quality of separate GPS satellite signals received also varies with vehicle location. In hilly or tree lined areas, built up areas with tall buildings, multistory car parks, garages, tunnels, bridges and during heavy rain/thunderstorms, signal reception of some or all of the GPS satellites will be poor or non existent.

A minimum of three separate GPS satellite signals are required for the navigation computer to calculate a three dimensional (3D) positional fix. When only two signals are being received, the navigation computer will calculate a less accurate two dimensional (2D) positional fix. The more widely dispersed that the GPS satellites are, the more accurate the positional fix. The navigation computer can store information from a maximum of 12 GPS satellites at any one time. When more than three signals are stored, the navigation computer selects the three most widely dispersed signals for the position calculation.



Where fitted, the CARiN III and Trafficmaster system combines a satellite navigation system (CARiN III) with a real-time traffic information system (Trafficmaster).

The satellite navigation system provides computer generated audible and visual route guidance information to enable the driver to reach a desired destination. The system allows the driver to choose between road navigation and off-road navigation, and to incorporate waypoints. Road navigation also allows the driver to choose between using minor or major roads and the quickest or shortest route. Directions to hospitals, museums, monuments, hotels etc. are also available. The computer uses map information stored on a CD-ROM to determine the best route for the journey and provide the driver with details of directions and approaching junctions. The current position of the vehicle is determined using a combination of vehicle sensor inputs and the Global Positioning System (GPS).

The Trafficmaster system displays live traffic flow information on the road navigation map screens. Traffic speed is indicated on the maps by color coded roads and arrows. The traffic flow information is relayed from a network of sensors covering motorways and trunk roads. Data from the sensors is updated on a three minute cycle, 24 hours a day, 365 days a year.

The navigation system consists of the following components:

scientia non olet · About LEMON Manuals