Radar cross-section of pedestrians in the low-THz band

Low-terahertz (THz) (above 150 GHz) radar sensing is one of the promising technologies to provide safe navigation for autonomous cars due to its expected high-resolution imaging capability. It is anticipated that for robust operation at high levels of autonomy the sensor suite should provide a fusion of video and radar data and its efficiency depends on radar ability to deliver a resolution high enough to be compatible with that of the optical image. Performance of low-THz radar, capable to deliver required resolution, is considered in this study, with the focus on reflectivities of pedestrians at frequencies within the low-THz region - 150 and 300 GHz. Backscatter returns are collected in a controlled environment at a number of frequency bands and at different aspect angles. Measurement methodology is presented and several indicators of reflectivities are calculated. Results are compared with values of radar cross-section reported for current automotive frequency standards 24 and 77 GHz. The effect of clothing on reflectivities is also considered in this study.