Near-Earth Asteroids and the Arecibo Observatory Radar The Arecibo Observatory radar is the world's most powerful instrument for post-discovery characterization and orbital refinement of near-Earth asteroids. Arecibo radar observations are critical for identifying asteroids that might be on collision course with Earth and, if necessary, preventing a collision. ... A model of the primary component of asteroid 1999 KW4, derived from radar data. ...

... 2.3 Data acquisition Spectra generated by the Multibeam correlator contain the usual structure seen in spectra from other H i instruments: a bandpass spectrum which is the sum of the sky , ground and receiver temperatures multiplied by the product of the filters in the receiver chain; superimposed on this is a noise ... Note also that sources extended much beyond ,40 arcmin can be imaged poorly in HIPASS images because of the bandpass sidelobe effect described in Section 3.3. ...