Automotive navigation system

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A taxi in Kyoto, equipped with GPS navigation system
A taxi in Kyoto, equipped with GPS navigation system

An automotive navigation system is a satellite navigation system designed for use in automobiles. It typically uses GPS to acquire position data to locate the user on a road in the unit's map database. Using the road database, the unit can give directions to other locations along roads also in its database. Dead reckoning using distance data from sensors attached to the drivetrain and a gyroscope can be used for greater reliability, as GPS signal loss and/or multipath can occur due to urban canyons or tunnels.

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Accuracy dispute
 This article or section appears to contradict itself about who created the first automotive navigation system. Please help fix this problem.

Alpine claims they created the first automotive navigation system in 1981.[citation needed]

Honda claims[1] to have created the first navigation system starting in 1983, and culminating with general availability in the 1990 Acura Legend. This analog system used an accelerometer to navigate using inertial navigation, as the GPS system was not yet generally available.

Both Mitsubishi Electric[2] and Pioneer[3] claim to be the first with a GPS-based auto navigation system, in 1990. Also in 1990, a draft patent application was filed within Digital Equipment Co. Ltd. for a multi-function device called PageLink that had real-time maps for use in a car listed as one of its functions.

Magellan, a GPS navigation system manufacturer, claims[4] to have created the first GPS-based vehicle navigation system in the U.S. in 1995.

GPS Navigation System using TomTom software
GPS Navigation System using TomTom software

Navigation systems may (or may not) use a combination of any of the following:

  • top view for the map
  • top view for the map with the map rotating like the automobile
  • bird's-eye view for the map or the next curve
  • linear gauge for distance, which is redundant if a rotating map is used
  • numbers for distance
  • schematic pictograms
  • voice prompts

The road database is a vector map of some area of interest. Street names or numbers and house numbers are encoded as geographic coordinates so that the user can find some desired destination by street address (see map database management).

Points of interest (waypoints) will also be stored with their geographic coordinates. Point of interest specialties include speed cameras, fuel stations, public parking, and "parked here" (or "you parked here").

Contents can be produced by the user base as their cars drive along existing streets (Wi-Fi) and communicating via the internet, yielding a free and up-to-date map.

Formats are almost uniformly proprietary; there is no industry standard for satellite navigation maps, although Navteq are currently trying to address this with S-Dal (see below).

The map vendors Tele Atlas and NAVTEQ create the base map in a standard format GDF, but each electronics manufacturer compiles it in an optimized, usually proprietary format. GDF is not a CD standard for car navigation systems. GDF is used and converted onto the CD-ROM in the internal format of the navigation system.

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 It has been suggested that this section be split into a new article. (Discuss)

CARiN Database Format (CDF) is a proprietary navigation map format created by Philips Car Systems (this branch was sold to Mannesman VDO, now VDO/Dayton in 1998) and is used in a number of navigation-equipped vehicles. The 'CARiN' portmanteau is derived from Car Information and Navigation.

The first navigation computers using this map format used the Microware OS9000 operating system, however newer variants such as the BMW iDrive and VDO/Dayton PN2050 use Windows CE[1]

The original system uses CD-ROM-based maps, with ISO Level 1 encoding for their file system. Map media can be recognized by the presence of the following files on the CD:

  • ABSTRACT
  • BIBLIOGR
  • CARINET
  • CARINDB
  • COPYRIGH

Newer derivatives also use flash memory and DVD-ROM-based maps, for extra capacity and to add support for long file names. Older CARiN-compatible navigation computers are not able to read the newer DVD maps, but the DVD-enabled computers are still able to read the CD-based maps.

Vehicle manufacturers who have used or are still using this format in one or more of their ranges include:

After-market GPS vendors using the format include:

Older CD-based CARiN maps are completely interchangeable between manufacturers; however, differences in the more modern DVD and flash memory maps are starting to change this.

Point of Interest information can be stored either in the database file itself (usually called "carindb"), or in a separate database under a directory named 'TPD.' Encoding of GPS coordinates in the TPD folder is proprietary and varies between navigation computers (e.g., BMW 'HIGH' vs BMW 'Professional' editions of the navigation map). Editors are now available to customize these POI.

CARiN media is sometimes referred to colloquially as "Carinet" or "CarinDb," after the names of the files on the navigation media.

This is a proprietary map format published by Navteq, who have released it royalty free for the purpose of making it an industry standard for digital navigation maps. Vendors currently using this format include:

The road database may be stored in solid state read-only memory (ROM), optical media (CD or DVD), solid state flash memory, magnetic media (hard disk), or a combination. A common scheme is to have a base map permanently stored in ROM that can be augmented with detailed information for a region the user is interested in. A ROM is always programmed at the factory; the other media may be preprogrammed, downloaded from a CD or DVD via a computer or wireless connection (bluetooth, Wi-Fi), or directly used utilizing a card reader.

Some navigation device makers provide free map updates for their customers. These updates are often obtained from the vendor's website, which is accessed by connecting the navigation device to a PC.

Some newer systems can not only give precise driving directions, they can also receive and display information on traffic congestion and suggest alternate routes. These may use either TMC, which delivers coded traffic information using radio RDS, or by GPRS/3G data transmission via mobile phones.

One key type of real-time data is Traffic information, which includes:

  • Real-time data about free/full parkings;
  • Nearest public transport lines and prices, to go to a destination, when there is a jam.

Other real-time data includes weather broadcasting, etc.

Vehicles produced by Subaru and Lexus, as well as Lexus' parent company, Toyota, lock out many of the features when the vehicle is in motion. The manufacturers claim this is a safety feature to avoid the driver's being distracted. Many users have complained that passengers are not able to enter destinations while in motion, even though it is safe to do so. Additionally, drivers have complained that it is often more dangerous to pull off a highway and stop than it would be to enter a destination into the system. An explicit acknowledgement that the operator of the nav system is acting only as navigator and not as driver has been proposed as an option. This would relieve the car manufacturer of legal liabilities and restore full functionality.

A number of road accidents have been attributed to misdirection by satnav systems. On 11 May 2007, a driver followed satnav instructions in the dark and her car was hit by a train on a rail crossing that was not shown on the system.[2] In Exton, Hampshire, the County Council erected a sign warning drivers to ignore their "sat nav" system and to take another route, because the street was too narrow for vehicular traffic, and property damage resulted from vehicles getting stuck.[3]

In July 2007, an Australian man successfully overturned a speeding conviction after evidence from a GPS navigational track proved that he did not exceed the speed limit.[4]

  • Golf Carts may have integrated GPS units tailored to specific golf courses, providing interactive course maps and live readings of distance measurements to the green.
  • Many systems can give information on nearby points of interest (POIs), such as restaurants, cash machines and gas stations. Some navigation devices use this feature to store the location of known speed traps or speed cameras, and can alert the driver in much the same way as a radar detector. GPS may also be integrated into actual radar detection devices to enhance accuracy, and in some cases, implement a logic system where the system only alerts if the driver is traveling above the speed limit or in the direction to be 'caught.' Unlike radar detectors, GPS-based speed trap warnings are currently not illegal in any country except Switzerland.
  • GPS replaces the radio-dispatch of some taxis in Taiwan and Singapore. A central computer tracks all vehicles in the fleet/network, and automatically dispatches the closest cab within proximity of the customer's location to answer the call. To order a cab, the customer can either talk to an attendant or enter a registered location code for systematic service. The driver would enter an ETA (estimated time of arrival) on the computer, which is relayed to the caller by a prerecorded message, at which point a confirmation can be made to accept or reject the cab.
  • Advanced car security vehicle tracking systems can relay the vehicle's location via cellular phone services in case of loss or theft. The technology can also be used to manage fleet vehicles, in which case it's known as automatic vehicle location.

A vehicle can be retrofitted with a GPS unit if it did not originally have one. There are three approaches that can be taken here:

This type of installation is not permanently integrated into the vehicle, having only a simple bracket to mount the device on the surface of the dashboard and powered via the car cigarette lighter. This class of GPS unit does not require professional installation and can typically be used as handheld device, too.

Benefits of this type of GPS unit include low cost as well as the ability to move them easily to other vehicles. However, their portability also means they are easily stolen if left inside the vehicle. Furthermore, not having a magnetic compass and being unable to use inputs from the vehicle's speed sensors, means that they cannot use dead reckoning in tunnels where there's no GPS signal.

A portable automotive navigation system kit generally includes:

Many vehicle manufacturers offer GPS as an option in their vehicles. Customers whose vehicles did not ship with GPS can therefore purchase and retrofit the original factory-supplied GPS unit. In some cases this can be a straightforward 'plug-and-play' installation if the required wiring harness is already present in the vehicle. However, with some manufacturers, new wiring is required, making the installation more complex.

The primary benefit of this approach an integrated and factory-standard installation. Many original systems also contain a gyrocompass or accelerometer and may accept input from the vehicle's speed sensors, thereby allowing them to navigate via dead reckoning when a GPS signal is temporarily unavailable. However, the costs can be considerably higher than other options. In some cases, it may even be more economical to buy a similar vehicle that already has a factory-fitted GPS.

A number of manufacturers supply aftermarket GPS units that can be integrated permanently into the vehicle. A typical location for such an installation is the DIN slot for the radio/tape/CD. However, in extreme cases, the dashboard may also be remodeled to accommodate the unit.

This approach can be considered a tradeoff between the previous two options. Benefits include a more secure and better cosmetic finish than a portable device, and lower cost compared to the installation of an original factory-supplied GPS.

Commercial navigation software is widely available for most current smartphones as well as some Java-enabled phones that allows them to use an internal or external GPS receiver (in the latter case, connecting via serial or Bluetooth). Phones with this capability function no differently to a dedicated portable GPS receiver and may even use the same software.

More bespoke solutions also exist for mobile phones with inbuilt GPS capabilities. One such example is marketed by Verizon Wireless in the United States, and is called VZ Navigator. The system uses gpsOne technology to determine a person's location, and then uses the mobile phone's data connection to download maps and calculate navigational routes.

Establishing points of interest in real-time and transmitting them via GSM cellular telephone networks using the Short Message Service (SMS) is referred to as Gps2sms.

Some vehicles and vessels are equipped with hardware that is able to automatically send an SMS text message when a particular event happens, such as:

  • Theft
  • Anchor drift
  • Breakdown

The receiving party (e.g., a tow truck) can store the waypoint in a computer system, draw a map indicating the location, or see it in an automotive navigation system.

  1. ^ Microsoft (March 4, 2002). "Microsoft Technology Hits the Road in BMW 7 Series". Press release.
  2. ^ "Woman runs for her life after satnav leads her into path of a train", Daily Mail, May 11, 2007. 
  3. ^ "HGVs told to ignore sat-nav guide", BBC News, Feb 19, 2007. 
  4. ^ "GPS beats radar gun", Herald Sun, June 2, 2007. 


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