The Global Positioning System (GPS) is now widely applied to land, sea, and air navigation. One of its biggest disadvantages is that the accuracy of a standard GPS is about 100m for 95% of the time, so that it cannot be used effectively for vehicle navigation. Differential GPS (dGPS) systems are more accurate than standard GPS systems. This paper presents the results of a study to assess the performance of dGPS systems in London, based on marine radio beacons. It briefly examines the Landstar, Omnistar, and Focus FM dGPS services, and covers the marine-based services in more detail, including a table and a map of radio beacons in the UK. It describes the experimental set-up and static and dynamic tests for dGPS corrections in London, based on radio beacons. The dynamic tests included collection of dGPS performance data and map-based position data. The results show that the dGPS signals, based on standard marine radio beacons, can be used in London to correct GPS errors. Measurements in different parts of London show that the expected horizontal position accuracy is about 10m for 95% of the time, when an ordinary low-end GPS unit is used with a radio beacon dGPS receiver. This is accurate enough for most land-based Intelligent Transport System (ITS) applications, but not for some real-time ITS applications such as driverless automatic vehicle control systems.

  • Availability:
  • Corporate Authors:

    Hemming Group, Limited

    32 Vauxhall Bridge Road
    London,   United Kingdom  SW1V 2SS
  • Authors:
    • Ibrahim, D
  • Publication Date: 2000-6


  • English

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Filing Info

  • Accession Number: 00798040
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD
  • Created Date: Sep 8 2000 12:00AM