Radar cross section measurements of pedestrian dummies and humans in the 24/77 GHz frequency bands : establishment of a reference library of RCS signatures of pedestrian dummies in the automotive radar bands

Road safety has become a major societal issue that should not be ignored. At present, a wide range of new technologies, including intelligent speed adaptation and collision avoidance systems, are being introduced to improve road safety levels and reduce these casualties. Among the various types of collision avoidance systems, automotive short-range radars (SRRs) are those most widely deployed. A recent Communication of the European Commission (i.e., SEC(2010) 903) has stated that a wide deployment of SRR systems could help to reach the EU's policy goal of halving the number of deaths on the road. In this context, it is very important to make sure that the SRR signatures of pedestrian dummies match those of humans with a high degree of accuracy. This report summarizes the results of an extensive series of radar cross section (RCS) laboratory measurements on pedestrian dummies and humans completed in August 2012 at the European Microwave Signature Laboratory of the EC Joint Research Centre. This measurement campaign has allowed the establishment of a reference library with the RCS signatures of pedestrian dummies and humans in the 24 GHz and 77 GHz bands, which are those currently allocated for automotive SRR systems. Results show for the first time that the observed global frequency/azimuth RCS averages in the two frequency bands are very close to each other. A significant impact of the pedestrian height on the observed RCS, particularly at 77 GHz, has also been noted. A first qualitative comparison of the RCS signatures between dummies and humans was also completed. and showed that the RCS averages of the available dummies are slightly below those of the humans. Finally, following a dedicated series of measurements, it has been observed that the impact of the clothing on the measured signatures is minimal except for those cases where some very thick clothes were worn.