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1
artículo
Modern high-power, large-aperture (HPLA) radars have been used in a variety of investigations including the investigation of meteoroid fragmentation. The identification of fragmentation has been based on a detailed interpretation, based on radio science, of head- and trail-echo properties. We now extend the discussion of fragmenting meteoroids to include apparent high-altitude (130–180 km) meteors observed at the Jicamarca Radio Observatory (JRO). While there have been a few reports of high-altitude meteors observed both optically and with radar, the meteor radar community has remained sceptical, with suspicions of antenna side-lobe contamination being the most commonly raised objection. We report results from two sets of meteor observations carried out at JRO in 2010 April. Our findings include meteoroid fragmentation results that are similar to those from the Arecibo VHF radar. These...
2
artículo
The Jicamarca Radio Observatory (JRO) main 50-MHz array antenna radar system with multiple receivers is being used to study meteors via two interferometric receiving modes. One of the major challenges in these studies is the phase calibration of the various receiver (interferometric) channels (legs). While investigating some ambiguous features in meteor head-echo results, we developed a ‘new’ calibration technique that employs satellite observations to produce more accurate phase and pattern measurements than were previously available. This calibration technique, which resolves head-echo ambiguities, uses the fact that Earth-orbiting satellites are in gravitationally well-defined orbits and thus the pulse-to-pulse radar returns must be consistent (coherent) for an entire satellite pass through the radar beam. In particular, the satellite yields a reliable point source for phase and t...