Speed measure of vehicles with on-board Doppler radar

The system configuration of an on-board Doppler radar system is presented which is based on millimeter wave frontends (61 GHz) and digital processing of baseband signals. For the estimation of the Doppler frequency a novel method is used which is based on FFT-techniques and on sensor model based algorithms for postprocessing. Here postprocessing means that the measured Doppler spectra are correlated with theoretically calculated spectra. The signal processing algorithm has been implemented on two Motorola´s DSP 56001 with 24 bit fixpoint arithmetic. The first only serves as an interface to the 14 Bit A/D-converter running at 540 kHz conversion rate. The complete evaluation unit consists of one Euro sized PCB. With the realized Doppler radar system speed values up to 250 km/h can be measured with an update rate of 25 Hz