We have many traffic accidents and related fatalities every year and safety issue is focused very much as well as environmental issue. As for frontal collision, some products of Adaptive Cruise Control (ACC) System and headway distance warning system have been developed and introduced to the market in Japan, U.S, and Europe. In the other hand, the systems to reduce side and rear collision, for example, which assist driver's maneuvers in lane change situation at high speed, are under development. And efforts to make restraint systems such as airbag and seat belt more effective is also needed in order to increase passive safety and reduce related fatalities, for example, smart airbag using additional sensors.
Corresponding to these situations, we made a plan to develop short-range radars for these automotive applications, Blind Spot Detection System (BSD), Parking Aid System (PA), and Pre-crash Detection System (PC). And we developed a prototype pulse radar for a kind of BSD, Side Obstacle Warning System (SOWS), as the first generation of our short-range radar. In this paper, the configuration of this pulse radar is described and test results derived from evaluation tests are shown. Finally, the challenges related to improvement of this radar are discussed.