In this paper we review the main issues that are relevant for the detection of Extensive Air Showers (EAS) from space. EAS are produced by the interaction of Ultra-High Energy Cosmic Particles (UHECP) with the atmosphere and can be observed from an o
rbiting telescope by detecting air fluorescence UV light. We define the requirements and provide the main formulas and plots needed to design and optimize a suitable telescope. We finally estimate its expected performances in ideal conditions.
Future detection of Extensive Air Showers (EAS) produced by Ultra High Energy Cosmic Particles (UHECP) by means of space based fluorescence telescopes will open a new window on the universe and allow cosmic ray and neutrino astronomy at a level that
is virtually impossible for ground based detectors. In this paper we summarize the results obtained in the context of the EUSO project by means of a detailed Monte Carlo simulation of all the physical processes involved in the fluorescence technique, from the Extensive Air Shower development to the instrument response. Particular emphasis is given to modeling the light propagation in the atmosphere and the effect of clouds. Main results on energy threshold and resolution, direction resolution and Xmax determination are reported. Results are based on EUSO telescope design, but are also extended to larger and more sensitive detectors.
We summarise some basic issues relevant to the optimisation and design of space-based experiments for the observation of the Extensive Air Showers produced by Ultra-High Energy Cosmic Particles interacting with the atmosphere. A number of basic relat
ions is derived and discussed with a twofold goal: defining requirements for the experimental apparatus and estimating the exptected performance.
