Performances of JEM-EUSO: angular reconstruction The JEM-EUSO Collaboration

Mounted on the International Space Station(ISS), the Extreme UniverseSpace Observatory, on-board the Japanese Experimental Module (JEM-EUSO),relies on the well established fluorescence technique to observe Extensive Air Showers (EAS) developing in the earth?s atmosphere. Focusing on the detection of Ultra High Energy Cosmic Rays (UHECR) in the decade of 10 20 eV, JEM-EUSO will face new challenges by applying this technique from space. The EUSO Simulation and Analysis Framework (ESAF) has been developed in this context to provide a full end-to-end simulation frame, and assess the overall performance of the detector.Within ESAF, angular reconstruction can be separated into two conceptually different steps. The first step is pattern recognition, or filtering, of the signal to separate it from the background. The second step is to perform different types of fitting in order to search for the relevant geometrical parameters that best describe the previously selected signal. In this paper, we discuss some of the techniques we haveimplemented in ESAF to perform the geometrical reconstruction of EAS seen by JEM-EUSO. We also conduct thorough tests to assess the performances of these techniques in conditions which are relevant to the scope of the JEM-EUSO mission. We conclude by showing the expected angular resolution in the energy range that JEM-EUSO is expected to observe. Fil: Adams, J. H.. University of Alabama in Huntsville; Estados Unidos Fil: Ahmad, S.. Ecole Polytechnique; Francia Fil: Albert, J. N.. Univ Paris-Sud; Francia Fil: Allard, D.. Univ Paris Diderot; Francia Fil: Anchordoqui, L.. University of Wisconsin-Milwaukee; Estados Unidos Fil: Andreev, V.. University of California; Estados Unidos Fil: Anzalone, A.. INAF - Istituto di Astrofisica Spaziale e Fisica Cosmica di Palermo; Italia Fil: Arai, Y.. High Energy Accelerator Research Organization; Japón Fil: Asano, K.. Tokyo Institute of Technology; Japón Fil: Ave Pernas, M.. Universidad de Alcala (UAH); España Fil: Barrillon, P.. Univ Paris-Sud; Francia Fil: Batsch, T.. National Centre for Nuclear Research; Polonia Fil: Bayer, J.. University of Tübingen; Alemania Fil: Bechini, R.. Universita’ di Torino; Italia Fil: Belenguer, T.. Instituto Nacional de Técnica Aeroespacial ; España Fil: Bellotti, R.. Istituto Nazionale di Fisica Nucleare; Italia Fil: Belov, K.. University of California; Estados Unidos Fil: Berlind, A. A.. Vanderbilt University; Estados Unidos Fil: Bertaina, M.. Istituto Nazionale di Fisica Nucleare; Italia Fil: Biermann, P. L.. Karlsruhe Institute of Technology; Alemania Fil: Biktemerova, S.. Joint Institute for Nuclear Research; Rusia Fil: Blaksley, C.. Univ Paris Diderot; Francia Fil: Blanc, N.. Swiss Center for Electronics and Microtechnology; Suiza Fil: Blecki, J.. Space Research Centre of the Polish Academy of Sciences; Polonia Fil: Blin-bondil, S.. Ecole Polytechnique; Francia Fil: Blumer, J.. Karlsruhe Institute of Technology; Alemania Fil: Bobik, P.. Institute of Experimental Physics; Eslovaquia Fil: Bogomilov, M.. University of Sofia; Bulgaria Fil: Bonamente, M.. University of Alabama in Huntsville; Estados Unidos Fil: Supanitsky, Alberto Daniel. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentina Fil: Guzman, A.. Institut f ur Astronomie und Astrophysik Tübingen; Alemania Fil: Mernik, T.. Institut fur Astronomie und Astrophysik Tübingen; Alemania Fil: The JEM-EUSO Collaboration.