  The Disp method is an algorithm that is used for reconstruction of primary
gamma ray direction in ground- based atmospheric Cherenkov telescope
experiments -measuring very-high-energy (VHE) gamma rays in the energy range
between 100GeV and 30 TeV. In general terms, the geometric information obtained
from one single shower image is sufficient for the algorithm to find the sky
location of the primary. Various versions of the Disp method were implemented
and used in the past. In this study, we present a multi-dimensional
implementation of the Disp method for the VERITAS instrument and show (using
Monte Carlo simulations and the Crab Nebula observations) that it significantly
improves the angular resolution for large-zenith-angle (LZA) observations. We
also applied the disp method to VERITAS data taken from the galactic center
region which is detected by VERITAS.
