A comprehensive assay of the micrometeor flux using extant and new radar head-echo measurements quantifies the amount and temporal variability of dust deposition into the earth's middle atmosphere. The data are used to construct a meteor input function model that will be useful to studies of ionospheric E-region layering, sporadic-E formation, and to the communications disturbances associated with those phenomena. Additionally, the information concerning meteor trajectories prior to earth-encounter are important for understanding dust in the inner solar system, planetary formation and evolution, and evolution of the asteroid belt.
