Radar Observations of Near-earth

Much useful information about physical and dynamical properties can be obtained from radar observations of near-Earth asteroids (NEAs) that come within reach of 1 Resolution of echoes in Doppler frequency and/or time groundbased radar telescopes . delay can be used to synthesize 1-D or 2-D images that show a target’s size, shape and rotation. Disc-integrated measurements also have value, because the wavelengths of NEA radar systems (3.5 or 13 cm) provide sensitivity to near-surface bulk density and structure larger than a few centimeters, and because metal, which is much more abundant in iron/stony-iron meteorites than chondrites, influences radar reflectivity dramatically y.