A simulation code to assist designing space missions of the Airwatch   type
  The design of an Airwatch type space mission can greatly benefit from a flexible simulation code for establishing the values of the main parameters of the experiment. We present here a code written for this purpose. The cosmic ray primary spectrum at very high energies, the atmosphere modelling, the fluorescence yield, the photon propagation and the detector response are taken into account in order to optimize the fundamental design parameters of the experiment, namely orbit height, field of view, mirror radius, number of pixels of the focal plane, threshold of photo-detection. The optimization criterion will be to maximize counting rates versus mission cost, which imposes limits both on weight and power consumption. Preliminary results on signals with changing energy and zenith angle of incident particles are shown. 
T. Montaruli (INFN Bari), R. Bellotti (U. of Bari), F. Cafagna (INFN   Bari), M. Circella (INFN Bari), C. N. De Marzo (U. of...