Analysis of modern observations of meteor showers based on PTM methods

The work is focused on the analysis of modern observations of meteoroids included in the data bank formed by both professional researchers and amateur astronomers. Based on the modern physical theory of meteoroids (PTM), a new method for analyzing measurements developed, which provides the accuracy comparable with the results of radar observations. Due to the fact that the accuracy of the new method for analyzing meteoroids observations has increased significantly, it became possible to process observations of the Perseid and Leonid showers over a period of 120 years. The use of PTM made it possible for the first time to explain the distribution of meteor echo signals observed at an altitude of 2 MHz, at which the upper part of this distribution refers to an altitude of 140 km. In the process of work, a database of orbital characteristics of meteoroids was created. A method has been developed for modeling the probability of hitting a certain area of a meteor particle with a mass greater than a certain specified value and determining the density of a meteor shower from radio observations as well as a new “tomography” method for calculating the density distribution of sporadic meteors in the sky using radar observations of meteors at the same station with a goniometer. The method allows calculating the density of a meteor shower on the celestial sphere with an angular resolution of 2°. The use of these methods served as a proof that the distribution density of meteoroid showers on the celestial sphere has two planes of symmetry: the first coincides with the plane of the ecliptic, passing through the poles of the Earth, the other one is perpendicular to the plane of the ecliptic.

Approximations for the Electron Density in Meteor Trails

Herlofsen (1947) has shown that an exact solution of the equations governing the evaporation of a meteor particle during its flight in the upper atmosphere can be obtained in the special case of a spherical meteor in an isothermal atmosphere. In terms of the number n of meteor atoms evaporated in unit length of trail, the electron density a is . (1)

The Incidence of Meteor Particles Upon the Earth

Radio echo rates for both shower and sporadic meteors, measured at Adelaide with the 27 Mcls C.W. equipment, are applied to the calculation of the incident flux of meteors above limiting brightnesses in the range MR < + 7�5. On the hypothesis of a strongly velocity-dependent ionizing probability, reached after a critical evaluation of the observational material, the meteor flux above prescribed limiting meteor particle masses, and the space densities of meteor particles, are also calculated. These fluxes and densities agree reasonably well with independent evaluations from visual meteor rates. The amount of meteoric matter falling on the whole Earth per day within particle mass limits 10?1 to 10?4 g, for sporadic meteors and some showers, is also estimated.