Dynamical behavior of meteoroids in the atmosphere derived from very precise photographic records

Basic equations of motion and ablation of a single non-fragmenting body thr ough the atmosphere were solved with ablation and shape-density coefficient s as general functions of time. This solution was applied to 22 photographi cally recorded meteoroids with very precise data available, such meteoroids which did not yield solutions by using the gross-fragmentation model. Extr emely high values of the shape density coefficient, fi, at the early parts of the luminous trajectory are the main reason for non-existing gross-fragm entation solutions. Reasons for such high values of K are examined in some detail, including analysis of spectral records available for one of the met eoroids. Also positive values of acceleration well outside standard deviati ons were documented for several meteors. Such cases cannot be interpreted b y our model. We suspect that electric forces originating from the atmospher ic charges and from meteoroid charges (which were not included in the drag equation) are responsible for the observed very high values of the shape-de nsity coefficient at the early parts of meteoroid trajectories.