Abstract
With the increasing costs of vehicle fleet operations, knowledge of the whereabouts and availability of vehicles is important. Current technology has made viable on-board automatic vehicle-location systems, linked by radio telemetry to base command and control systems, for fleet operations such as police, ambulance, utilities and bus companies. The Marconi "Landfall" system is described in detail, with an account of the research and development underlying its design, and the tracking algorithms and telemetry protocols.