Precise orbit determination of meteors using a radar and an optical sensor

Impacts of meteors with spacecraft are among the major sources of possible problems in the space environment. Although the average mass of meteor bodies is much less than artificial space debris, the relative velocity of high-speed meteors against the Earth reaches 72 km/s, which far exceeds that of artificial objects. It is thus very important to establish the statistics of meteors, especially those of the mass and velocity, along the Earth's orbit around the Sun in order to make a reliable data base for designing large scale spacecraft such as space stations. Radar with the help of an optical camera are most suited for this purpose. The purpose of the present paper is to develop a high- sensitivity combined radar-optical system consisting of a high-power VHF Doppler radar and an ICCD video camera for the purpose of studying the velocity and mass distributions of faint meteors. A description of the systems and their performance evaluations are given. Preliminary results of the mass estimates and the relations of the radar echo power and the absolute visual magnitude derived from test experiments are also presented.