Radar surveys of meteoroid orbits

Summary Radar facilities providing routine measurements of the heliocentric orbits of meteoroids are valuable in providing a data-base of the orbital characteristics of the solar system small body population in the mass range about 10^–2 down to 10^–6 g. Such an orbital information background is essential for an understanding of the evolutionary processes of this component.An outline is presented of orbit-finding systems; their inherent limitations and associated selection effects with some emphasis given to the on-going southern hemisphere routine survey provided by the AMOR facility which provides orbits down to a limiting magnitude +13.