4 research outputs found
Perception Through 2D-MIMO FMCW Automotive Radar Under Adverse Weather
Millimeter-wave (mmWave) radars are being increasingly integrated in
commercial vehicles to support new Adaptive Driver Assisted Systems (ADAS)
features that require accurate location and Doppler velocity estimates of
objects, independent of environmental conditions. To explore radar-based ADAS
applications, we have updated our test-bed with Texas Instrument's 4-chip
cascaded FMCW radar (TIDEP-01012) that forms a non-uniform 2D MIMO virtual
array. In this paper, we develop the necessary received signal models for
applying different direction of arrival (DoA) estimation algorithms and
experimentally validating their performance on formed virtual array under
controlled scenarios. To test the robustness of mmWave radars under adverse
weather conditions, we collected raw radar dataset (I-Q samples post
demodulated) for various objects by a driven vehicle-mounted platform,
specifically for snowy and foggy situations where cameras are largely
ineffective. Initial results from radar imaging algorithms to this dataset are
presented.Comment: 5 page
Millimeter Wave High Resolution Radar Accuracy in Fog Conditions—Theory and Experimental Verification
Attenuation and group delay effects on millimeter wave (MMW) propagation in clouds and fog are studied theoretically and verified experimentally using high resolution radar in an indoor space filled with artificial fog. In the theoretical analysis, the frequency-dependent attenuation and group delay were derived via the permittivity of the medium. The results are applied to modify the millimeter-wave propagation model (MPM) and employed to study the effect of fog and cloud on the accuracy of the Frequency-Modulated Continuous-Wave (FMCW) radar operating in millimeter wavelengths. Artificial fog was generated in the experimental study to demonstrate ultra-low visibility in a confined space. The resulted attenuation and group delay were measured using FMCW radar operating at 320–330 GHz. It was found that apart from the attenuation, the incremental group delay caused by the fog also played a role in the accuracy of the radar. The results were compared to the analytical model. It was shown that although the artificial fog has slight different characteristics compare to the natural fog and clouds, in particle composition, size, and density, the model predictions were good, pointing out that the dispersive effects should be considered in the design of remote sensing radars operating in millimeter and sub-millimeter wavelengths