3D Meteoroid TrajectoriesOPEN ACCESS
Eleanor K. Sansom, Trent Jansen-Sturgeon, Mark G. Rutten, Phil A. Bland, Hadrien A. R. Devillepoix, Robert M. Howie, Morgan A. Cox, Martin C. Towner, Martin Cupak, Benjamin A. D. Hartig
submitted to Icarus
(abstract changed on 2 July)
“Meteoroid modelling of ﬁreball data typically uses a one dimensional model along a straight line triangulated trajectory. The assumption of a straight line trajectory has been considered an acceptable simpliﬁcation for ﬁreballs, but it has not been rigorously tested. The unique capability of the Desert Fireball Network (DFN) to triangulate discrete observation times gives the opportunity to investigate the deviation of a meteoroid’s position to diﬀerent model ﬁts. Here we assess the viability of a straight line assumption for ﬁreball data in two meteorite-dropping test cases observed by the Desert Fireball Network (DFN) in Australia – one over 21 seconds (DN151212 03 ), one under 5 seconds (DN160410 03 ). We show that a straight line is not valid for these two meteorite dropping events and propose a three dimensional particle ﬁlter to model meteoroid positions without any straight line constraints. The single body equations in three dimensions, along with the luminosity
equation, are applied to the particle ﬁlter methodology described by Sansom et al. (2017). Modelling ﬁreball camera network data in three dimensions has not previously been attempted. This allows the raw astrometric, line-of-sight observations to be incorporated directly. In analysing these two DFN events, the triangulated positions based on a straight line assumption result in the modelled meteoroid positions diverging up to 3.09 km from the calculated observed point (for DN151212 03 ). Even for the more typical ﬁreball event, DN160410 03, we see a divergence of up to 360 m. As DFN observations are typically precise to < 100 m, it is apparent that the assumption of a straight line is an oversimpliﬁcation that will aﬀect orbit calculations and meteorite search regions for a signiﬁcant fraction of events."