SIMULATIONS OF A GIANT HYBRID AIR SHOWER DETECTOR

We have used Monte Carlo simulations to investigate the capabilities o f a giant air shower observatory designed to detect showers initiated by cosmic rays with energies exceeding 10(19) eV. The observatory is t o consist of an array of detectors that will characterise the air show er at ground level, and optical detectors to measure the fluorescence light emitted by the shower in the atmosphere. Using these detectors t ogether in a 'hybrid' configuration, we find that precise geometrical reconstruction of the shower axis is possible, leading to excellent re solution in energy. The technique is also shown to provide very good r econstruction below 10(19) eV, at energies where the ground array is n ot fully efficient.