Vehicle natural speed detector - has aerial formed by collector lens with punctiform feed radiation source in focal plane

摘要

The device is esp. for track mounted vehicles for measuring the travelled distance by integration of velocity, using the Doppler shift of received waves in relation to radiated waves. It can be used for other vehicles and ships. The velocity is determined by transmitting from at least one aerial electromagnetic waves in the direction of the ground, using the back-radiation principle. Prior to the radiation the aerials are aligned in required manner to the vehicle long axis. The reflected wave portions are received via the aerial(s), and the velocity and/or travelling direction data are derived from the reflectively received waves, using the Doppler effect. The aerial comprises a collector lens with a punctiform radiation source in the focal plane of the lens. Pref. the lens is plano-convex, the convex surface facing the radiation source.