Arrangement for position-selective speed measurement using the doppler principle

摘要

When measuring speed over ground by means of microwave Doppler radar, signal noise, switching spikes and nearby reflectors reduce the measurement accuracy. In order to avoid these disadvantages, a reference signal which recurs with the period T.sub.0 and a target signal which follows the reference signal after a time interval T.sub.s are emitted via an antenna. That part of the reference signal which has already been received again during transmission of the target signal is subtracted from the target signal which is received later. The difference signal obtained in this way is a measurement signal from which interference spikes, signal noise and nearby reflectors have been largely removed.