Improved meteoroid trajectory and speed reconstruction with BRAMS: pre-t_0 phase technique and uncertainty analysis

We present an enhanced method for reconstructing meteoroid trajectories and speeds using the Belgian RAdio Meteor Stations (BRAMS) forward scatter network. A novel extension of the pre-t_0 phase technique, which was originally developed for backscatter radar, is adapted to continuous-wave forward scatter systems. By analyzing the phase evolution before the meteoroid reaches the specular reflection point, we derive precise speed estimates. These pre-t_0 speeds are integrated with time-of-flight measurements in an optimization solver, enabling trajectory determination without interferometry. A Markov Chain Monte Carlo framework propagates these measurement uncertainties, yielding robust confidence intervals on meteoroid trajectory and speed. Validation against optical data from the CAMS-BeNeLux network shows systematic improvements with mean speed errors <5% and inclination errors of 2-4 degrees.