High-altitude radar meteors observed at Jicamarca Radio Observatory using a multibaseline interferometric technique

Abstract

A new unambiguous, multibaseline interferometric technique was recently employed for meteor observations at Jicamarca Radio Observatory (JRO). These observations largely confirm high-altitude radar meteors (HARMs). The 50 MHz JRO array is arranged in contiguous quarter-arrays (Q) each of which is comprised of 4 × 4 sub-arrays (M), which are referred to as square modules in the Ochs’ manual. In these observations the radar transmission was from two quarter-arrays sharing a common diagonal. Signal reception was via three, quarter-array (Q) receivers and three adjacent (M) module receivers all of the same polarization. This arrangement offered the usual Q–Q and M–M interferometric baseline-pairs as well as new Q–M baselines that were rotated ∼6° from the Q–Q and M–M baselines. For relatively high signal-to-noise ratio meteors, this arrangement yields ambiguity resolution to the horizon and confirms the existence of HARM events. We report results from 2014 August 4 to 5 observations that include interesting new HARM events and also suggest the meteoric origin of high-altitude, altitude-extended transient events we named ‘Dragons’ in our earlier report (Gao & Mathews 2015a). We hope to extend this new technique with yet more baselines and higher sensitivity in near future observations.