Determining the parameters of fragmenting meteoroids from their braking in the atmosphere

The ballistic coefficients and ablation parameters of Prairie Network (United States) fireballs are determined by the best fitting in velocity-height variables. The braking trajectories based on the model of successive destruction with ablation are used as the test functions. The fitting accuracy of the observed trajectory was found to be approximately the same for the model of successive destruction and for the model of motion of a single body. At least, the fitting accuracy allows us neither to confirm nor to reject the fragmentation of meteoroids within the luminous segment of the trajectory. The previously noted excess of the observed luminosity of the fireballs studied here (Popova, 1997) over the value calculated for the dynamical mass, which was estimated from the model of a single body (Kulakov and Stulov 1992), can be explained by deviations of the meteoroid shapes from a sphere.