The Global Meteor Network -- Methodology and First Results

TL;DR

The paper describes the Global Meteor Network's methodology, including a novel calibration technique, and reports on its extensive data collection of meteoroid orbits, meteor shower analysis, and a detailed fireball case study, enhancing understanding of near-Earth meteoroids.

Contribution

Introduction of a new astrometry calibration method and deployment of a global, low-cost meteor detection network providing high-precision meteoroid data.

Findings

Over 220,000 meteoroid orbits collected since 2018.

All major annual meteor showers observed, including five outbursts.

Detailed analysis of a fireball with fragmentation and wake features.

Abstract

The Global Meteor Network (GMN) utilizes highly sensitive low-cost CMOS video cameras which run open-source meteor detection software on Raspberry Pi computers. Currently, over 450 GMN cameras in 30 countries are deployed. The main goal of the network is to provide long-term characterization of the radiants, flux, and size distribution of annual meteor showers and outbursts in the optical meteor mass range. The rapid 24-hour publication cycle the orbital data will enhance the public situational awareness of the near-Earth meteoroid environment. The GMN also aims to increase the number of instrumentally observed meteorite falls and the transparency of data reduction methods. A novel astrometry calibration method is presented which allows decoupling of the camera pointing from the distortion, and is used for frequent pointing calibrations through the night. Using wide-field cameras ($88^{\circ}\times48^{\circ}$) with a limiting stellar magnitude of $+6.0 \pm 0.5$ at 25 frames per second, over 220,000 precise meteoroid orbits were collected since December 2018 until June 2021. The median radiant precision of all computed trajectories is $0.47^{\circ}$, $0.32^{\circ}$ for $\sim20\%$ of meteors which were observed from 4+ stations, a precision sufficient to measure physical dispersions of meteor showers. All non-daytime annual established meteor showers were observed during that time, including five outbursts. An analysis of a meteorite-dropping fireball is presented which showed visible wake, fragmentation details, and several discernible fragments. It had spatial trajectory fit errors of only ~40 m, which translated into the estimated radiant and velocity errors of 3 arc minutes and tens of meters per second.