References and information sources

  • Sonnenberg, G.J. (1970). Radar and Electronic Navigation, 4th Edition. Newnes-Butterworths. ISBN 0408000031.
  • Banks, K. M. (1989). Integrated automatic vehicle location and position reporting system.
    Available from:
  • Banks, K. M. (1989). DATATRAK Automatic Vehicle Location and Position Reporting System. In: Conference Record of papers presented at the First Vehicle Navigation and Information Systems Conference (VNIS ’89), 0. IEEE.
    Available from:
    • Includes a lot of information about the 16-slot and 24-slot navigation slot structure, and the UHF back-channel.
    • Also includes information on what can be assumed to be the Mk1 Locator (68008 processor, -110dBm RF sensitivity)
  • Banks, K. M. (1991). Datatrak automatic vehicle location system in operational use in the UK. In: Vehicle Navigation and Information Systems Conference, 1991, IEEE.
    Available from:
    • Expands on Banks' earlier (1989) paper, giving more information on system accuracy and the setup of the navigation transmitters.
    • Contains some information on the versions of Datatrak Locator hardware available at the time, apparently Mk.I and Mk.II.
    • Installation cost is quoted as being under £1,000 in 1991, equivalent to roughly £2,195 in 2020.
  • Hofmann-Wellenhof, B., Wieser, M. and Legat, K. (2003). Navigation: Principles of Positioning and Guidance. Wien: Springer, pp.156-158.
    • Good summary of Datatrak. Explains the network structure, the 150km blanking distance, and the three-step (super-coarse, coarse, fine) navigation process.
  • Scorer, T., & Last, D. (1995). The Current Status of the Securicor Datatrak System. Journal of Navigation, 48(2), 204-214. doi:10.1017/S0373463300012662
  • Scorer, A. G. (1991). The Development of Datatrak. Journal of Navigation, 44(01), 37–47.
    Available from:
  • Dawes, S. R. (2001). Datatrak Network Radio Access Interface Specification. Datatrak Technical Specification No. T0062.
    Available from:, linked from this page.
  • Antenna
  • Locator and algorithms
    • Crompton, E.W.: Mobile transmitter/receiver. European patent EP0292182B1.
    • De la Salle, Paul G. and Cousins, Nigel J.: Method and apparatus for determining the position of an object within lanes determined utilizing two independent techniques. US patent US5402348A.
      • Covers the coarse/fine acquisition process and lane estimation.
      • Includes information on the three-LOP position error calculation.

“Vectorsum”, Digital Spy forums, 14th April 2016.

A Datatrak mast, eh? I didn't know any of those were still standing…. OT for the 'AM Deathwatch', but I worked for Securicor in the early nineties, with the PMR tentacle down in Radstock, in what was then Avon.

The techs downstairs who had been trained to service the Datatrak VHF/UHF uplink units would talk now and again about how the 'RF module' was a bare push-pull power FET stage connected pretty much directly to the antenna. The uplink was a time division system over all units using that frequency everywhere in the UK and Ireland, and had such a miniscule duty cycle that neither any ATU nor any heatsinking was required for the RF stage.

I would love to have actually seen one, but none came into the workshop in the year I was around as they were, quite literally, bomb-proof.
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  • Last modified: 2022/05/17 00:44
  • by philpem