Automated highway radar guidance antenna and system testing results

The Ohio State University ElectroScience Laboratory participated along with the Center for Intelligent Transportation Research as one of six teams to demonstrate an automated highway concept at the National Automated Highway Demo at San Diego in August, 1997. The forward looking radar concept which was demonstrated used a FSS highway stripe. This paper begins by describing the (patented) highway stripe and the forward-looking radar guidance concept. The radar system as implemented for automated guidance is described and present measured results on the system antenna array and on the system itself are given. In addition, results of the demonstration in San Diego are discussed. The forward-looking radar guidance concept is intended to be one more application for the wide variety of forward-looking radars which are being investigated by the automobile community. The FSS Highway Stripe provides an inexpensive way to create a strong echo with a unique signature, attached to the highway, so that the forward-looking radar can be used as an all-weather guidance sensor for an automated automobile. The radar used a monopulse guidance architecture. The antenna array used a single transmit horn, and a matched pair of receive horns, all vertically polarized. All three antennas were nestled into the composite front bumper beam. Performance data on the antennas and the steering sensing information are presented. The radar system was a chirp radar covering a frequency spectrum of 10 to 11 GHz. The narrow frequency of the FSS radar stripe occurred at 10.95 GHz, allowing its signature to be distinguished from the return of vehicles and other objects out in front of the vehicle. Radar system measured results in the highway situation are presented.