Automatic Vehicle Location

Automatic Vehicle Location
An Introduction

Prof. David Bernstein
James Madison University

Computer Science Department

bernstdh@jmu.edu

History

Traditional techniques for location determination (sometimes called "navigation", though it is clearly only part of the process of navigation) required human involvement
Recent advances in communications and computing technologies have made it possible to automate the process

Dead Reckoning Systems

Defined:
- Measure the speed and the heading (or the velocity vector) and "integrate" from a known location
Requirements:
- Speedometer (in the vehicle)
- Compass (in the vehicle)

Beacon (or Sign Post) Systems

Defined:
- Transmit the location from a sign post with known location
Requirements:
- Sign posts (at intersections) each with its own transmitter
- Receiver (in the vehicle)
- An optional range-finder (in the vehicle) can be used to improve the accuracy

Terrestrial Triangulation Systems

Defined:
- Use signals broadcast from several locations on the ground to determine the location using triangulation
Requirements:
- Transmitters (spaced-out on the ground)
- Receiver (in the vehicle)

Celestial Triangulation Systems

Defined:
- Use signals broadcast from satellites to determine the location using triangulation
Requirements:
- Transmitters (in satellites)
- Receiver (in the vehicle)
- A ground station at a known location equipped with a receiver and transmitter can be used to improve the accuracy
Examples:
- The US's Global Positioning System (GPS), Russia's Global Navigation Satellite System (GLONASS), China's BeiDou System (BDS), EU's Galileo Global Navigation Satellite System (GNSS)