All‐sky imaging of meteor trails at 55.25 MHz with the first station of the Long Wavelength Array

Abstract

A new capability for high‐sensitivity, all‐sky monitoring of VHF meteor trail reflections with the first station of the Long Wavelength Array, or “LWA1,” is described. LWA1 is a ∼100 m diameter HF/VHF array of 256 crossed‐dipole antennas with a unique transient buffer mode that allows it to monitor for meteor trails via all‐sky imaging with the same sensitivity as a single‐dish antenna in diameter. To demonstrate this capability, we have used a 2 h observing run conducted in August 2012 aimed at detecting and characterizing meteor trail reflections of analog TV transmissions at 55.25 MHz. The analysis techniques described here allowed for a detection rate of ∼9500 trails per hour, including the detection of two meteor streams with radiants in the Aries/Perseus and Aquila/Hercules regions that were not previously reported in the literature. In addition, we have found a population of relatively long‐duration (∼1 to a few minutes), typically faint trails. These trails have implied horizontal speeds of 15–130 m s −1 , with a typical speed of ∼30 m s −1 . We have also used high‐resolution time series of the brightest trails to characterize decay times over a relatively large geographical area (10°×7° in longitude and latitude) and on short (∼5 min) time scales. Potential enhancements that could be enabled by the addition of more LWA stations are discussed.