Nowadays hump velocity radar is usually installed at trackside

using Doppler principle to measure truck velocity

one radar can only measure one track speed. So

based on principle of inverse synthetic aperture radar velocity measurement

radar is installed above truck line on one side

and mathematic model of radar echo is set up

and velocity estimation algorithm of self-focusing for rolling set of car is used. Simulation results show that the algorithm can accurately and continuously measure instantaneous speed of multi-lanes rolling set of car.