Hybrid Detection of UHECR with the Pierre Auger Observatory
  The Pierre Auger Observatory detects ultra-high energy cosmic rays by implementing two complementary air-shower techniques. The combination of a large ground array and fluorescence detectors, known as the "hybrid" concept, means that a rich variety of measurements can be made on a single shower, providing much improved information over what is possible with either detector alone. In this paper the hybrid reconstruction approach and its performance are described. 
Miguel Mostafa (1) (for the Pierre Auger Collaboration) ((1) Univ. of   Utah)