Observations of meteors in the Earth's atmosphere: Reducing data from dedicated double-station wide-angle cameras

Abstract: Meteoroids entering the Earth's atmosphere can be observed as meteors, thereby providing useful information on their formation and hence on their parent bodies. We developed a data reduction software package for double station meteor data from the SPOSH camera, which includes event detection, image geometric and radiometric calibration, radiant and speed estimates, trajectory and orbit determination, and meteor light curve recovery. The software package is designed to fully utilise the high photometric quality of SPOSH images. This will facilitate the detection of meteor streams and studies of their trajectories. We have run simulations to assess the performance of the software by estimating the radiants, speeds, and magnitudes of synthetic meteors and comparing them with the a priori values. The estimated uncertainties in radiant location had a zero mean with a median deviation between 0.03$^{\circ}$ and 0.11$^{\circ}$ for the right ascension and 0.02$^{\circ}$ and 0.07$^{\circ}$ for the declination. The estimated uncertainties for the speeds had a median deviation between 0.40 and 0.45 km s$^{-1}$. The brightness of synthetic meteors was estimated to within +0.01m. We have applied the software package to 177 real meteors acquired by the SPOSH camera. The median propagated uncertainties in geocentric right ascension and declination were found to be of 0.64$^{\circ}$ and 0.29$^{\circ}$, while the median propagated error in geocentric speed was 1.21 km $s^{-1}$.