Algorithm for retrieving the direction of EAS arrival for the SPHERE Telescope

Reconstruction of the direction of arrival of a high atmospheric atmosphere (EAS) is one of the goals of the SPHERE experiment. A new method is presented for the recovery of direction, it compares the time delays of photons in the PMT, transferred to the snow, with the model delays of the curved front of the EAS CR. The analyzed events are initiated by nuclei (H, N, Fe) arriving at zenith (10º, 15º, 20º) and azimuth angles (0-360º) with primary energies of 10 PeV and 30 PeV. This method gives average errors of about 3º for primary energies of 10 PeV at 500 m and 900 m, and about 2º for 30 PeV on average for two heights.