vsb-RADAR - A 35 GHz Doppler Radar For Velocity Distance And Acceleration Measurements On Railbound Vehicles

Certain problems associated with conventional vehicular speed sensing such as wheel slip or wheel lock can be avoided by employing a microwave sensing technique. A 35 GHz doppler-radar has been developed to measure velocity, distance and acceleration of railbound vehicles. This radar, the vsb-RADAR, employs a Gunn-Device, a wave-guide slot antenna and a digital signal processor to provide the measuring data. Because of the small dimensions of the entire microwave unit, (86 × 456 × 114) mm, the radar can be directly mounted to the locomotive bogie. In 1975 the system was developed and since then has been under continuing tests at the "Deutsche Bundesbahn" (DB), the German Federal Railway. Concerning distance measurements an accuracy of 0.1% standard deviation has been achieved. Velocity and acceleration is measured with an accuracy of 1 %. These data hold for the velocity range of 20 to 250 km/h.