Low Light Level Television Meteor Observations And Simulations

A new sample of low light level television observations was combined with meteor model simulations to deduce meteoroid structure. The observations constitute the largest sample of faint meteor trajectories currently available. Simulations of compact stone and dustball meteor models were conducted. The large diversity of observed trajectories were not reproduced by the models presented in this thesis.;The 1981 and 1982 double station low light level television observations produced 459 meteor trajectories in the mass range 10{dollar}\sp{lcub}-1{rcub}{dollar} to 10{dollar}\sp{lcub}-4{rcub}{dollar} grams. These trajectories exhibited large variations in beginning heights, vertical trail lengths and light curves. The variations were attributed to differing meteoroid structure and composition.;The simulated stone model trajectories were compared with observations and exhibited much smaller variations in beginning heights and F parameter values. On this basis, the low beginning height meteors cannot be attributed to stone meteoroids as suggested by some authors. Subsequent simulations of small stone grains released below their radiation ceiling generated skewed light curves.;The dustball model structure consisted of stone grains embedded in a lower boiling point glue. The dustball simulations included two types of grain release mechanisms and six different glues. The grains were of a uniform mass of 10{dollar}\sp{lcub}-6{rcub}{dollar} grams. Two grain release modes were examined. In the abrupt mode, the grains were released once the glue had been vaporized from the parent body. The quasi-continuous mode considered the release of grains as the glue was being vaporized. Cellulose and water were two of the glues used in the simulations. Four other glues were defined in terms of specific and latent heats characteristics of organic compounds. The simulated dustball model trajectories exhibited some variation in beginning heights, vertical trail lengths and F parameter values but were less than the observed variations. It was proposed that simulations which utilized a distribution of grain sizes should be conducted.;The consensus of the simulations and observations suggest that meteoroids are stone grains held together by some nonluminary substances. These grains probably have a distribution of masses, unique to each individual meteor. The other substances are unknown, however, organic compounds seem to be the most likely candidates