<P> Mathematically, automotive navigation is based on the shortest path problem, within graph theory, which examines how to identify the path that best meets some criteria (shortest, cheapest, fastest, etc .) between two points in a large network . </P> <P> Automotive navigation systems represent a convergence of a number of diverse technologies many of which have been available for many years, but were too costly or inaccessible . Limitations such as batteries, display, and processing power had to be overcome before the product became commercially viable . </P> <Ul> <Li> 1961: Hidetsugu Yagi designed a wireless - based navigation system . This design was still primitive and intended for military - use . </Li> <Li> 1966: General Motors Research (GMR) was working on a non-satellite - based navigation and assistance system called DAIR (Driver Aid, Information & Routing). After initial tests GM found that it was not a scalable or practical way to provide navigation assistance . Decades later, however, the concept would be reborn as OnStar (founded 1996). </Li> <Li> 1973: Japan's Ministry of International Trade and Industry (MITI) and Fuji Heavy Industries sponsored CATC (Comprehensive Automobile Traffic Control), a Japanese research project on automobile navigation systems . </Li> <Li> 1979: MITI established JSK (Association of Electronic Technology for Automobile Traffic and Driving) in Japan . </Li> <Li> 1980: Electronic Auto Compass with new mechanism on the Toyota Crown . </Li> <Li> 1981: The earlier research of CATC leads to the first generation of automobile navigation systems from Japanese companies Honda, Nissan and Toyota . They used dead reckoning technology . </Li> <Li> 1981: Honda's Electro Gyro - Cator was the first commercially available car navigation system . It used inertial navigation systems, which tracked the distance traveled, the start point, and direction headed . It was also the first with a map display . </Li> <Li> 1981: Navigation computer on the Toyota Celica (NAVICOM). </Li> <Li> 1983: Etak was founded . It made an early system that used map - matching to improve on dead reckoning instrumentation . Digital map information was stored on standard cassette tapes . </Li> <Li> 1987: Toyota introduced the World's first CD - ROM - based navigation system on the Toyota Crown . </Li> <Li> 1990: Mazda Eunos Cosmo became the first car with built - in GPS - navigation system </Li> <Li> 1991: Toyota introduced GPS car navigation on the Toyota Soarer . </Li> <Li> 1991: Mitsubishi introduced GPS car navigation on the Mitsubishi Debonair (MMCS: Mitsubishi Multi Communication System). </Li> <Li> 1992: Voice assisted GPS navigation system on the Toyota Celsior . </Li> <Li> 1993: The Austrian channel ORF airs a presentation of the software company bitMAP and its head Werner Liebig's invention, an electronic city map including street names and house numbers, using a satellite - based navigation system . bitMAP attends Comdex in Las Vegas the same year, but doesn't manage to market itself properly . </Li> <Li> 1994: BMW 7 series E38 first European model featuring GPS navigation . The navigation system was developed in cooperation with Philips (Philips CARIN). </Li> <Li> 1995: Oldsmobile introduced the first GPS navigation system available in a United States production car, called GuideStar . </Li> <Li> 1995: Device called "Mobile Assistant" or short, MASS, produced by Munich - based company ComRoad AG, won the title "Best Product in Mobile Computing" on CeBit by magazine Byte . It offered turn - by - turn navigation via wireless internet connection, with both GPS and speed sensor in the car . </Li> <Li> 1997: Navigation system using Differential GPS developed as a factory - installed option on the Toyota Prius </Li> <Li> 1998: First DVD - based navigation system introduced on the Toyota Progres . </Li> <Li> 2000: The United States made a more accurate GPS signal available for civilian use . </Li> <Li> 2003: Toyota introduced the first Hard disk drive - based navigation system and the industry's first DVD - based navigation system with a built - in Electronic throttle control </Li> <Li> 2007: Toyota introduced Map on Demand, a technology for distributing map updates to car navigation systems, developed as the first of its kind in the world </Li> <Li> 2008: World's first navigation system - linked brake assist function and Navigation system linked to Adaptive Variable Suspension System (NAVI / AI - AVS) on Toyota Crown </Li> </Ul> <Li> 1961: Hidetsugu Yagi designed a wireless - based navigation system . This design was still primitive and intended for military - use . </Li>

When was the first in car navigation sustem invented