... ASTEROID’S MOONS : DISCOVERY BY RADAR . ... Moons of known asteroids have a low position ambiguity, which makes their discovery with powerful ground-based radar much easier than the discovery of new asteroids or other objects of Solar System. ... The other technique is a direct detection of radar echo from an asteroid moon. ... However, the diameter of a ground-based fully-steerable reflector is limited by 120-150 m to make it possible to perform two different functions: focusing and tracking (fig. ...