Radio-wave emission due to hypervelocity impacts in relation to optical observation and projectile speed

Abstract A hypervelocity impact causes the emission of radio-waves in the microwave frequency range. In order to understand the features of the phenomena and eventually to clarify the mechanism of the radio-wave generation, two kinds of experiments were carried out. The first one is the simultaneous observation of the phenomena by the micro-wave detection and the optical imaging method. The second one is to investigate the microwave emission in relation to the speed of a projectile. This paper describes the experimental results, and compares the microwave and optical methods from the viewpoints of impact detection.