Mori, M.Asaoka, Y.Cannady, NicholasHams, ThomasKrizmanic, John F.Sakai, KenichiCALET Collaborationet al2022-08-102022-08-102021-07-02“High-Energy Gamma-ray Observations Using the CALorimetric Electron Telescope (CALET) on the ISS,” M. Mori and Y. Asaoka for the CALET Collaboration, Proceedings of Science: 36th International Cosmic Ray Conference, (Madison, WI), 586 (2019). https://doi.org/10.22323/1.358.0586https://doi.org/10.22323/1.358.0586http://hdl.handle.net/11603/2535936th International Cosmic Ray Conference -ICRC2019- July 24th - August 1st, 2019 Madison, WI, U.S.A.CALET Collaboration Authors: O. Adriani, Y. Akaike, K. Asano, Y. Asaoka, E. Berti, G. Bigongiari, W. R. Binns, M. Bongi, P. Brogi, A. Bruno, J. H. Buckley, N. Cannady, G. Castellini, C. Checchia, M. L. Cherry, G. Collazuol, K. Ebisawa, A. W. Ficklin, H. Fuke, S. Gonzi, T. G. Guzik, T. Hams, K. Hibino, M. Ichimura, K. Ioka, W. Ishizaki, M. H. Israel, K. Kasahara, J. Kataoka, R. Kataoka, Y. Katayose, C. Kato, N. Kawanaka, Y. Kawakubo, K. Kobayashi, K. Kohri, H. S. Krawczynski, J. F. Krizmanic, P. Maestro, P. S. Marrocchesi, A. M. Messineo, J.W. Mitchell, S. Miyake, A. A. Moiseev, M. Mori, N. Mori, H. M. Motz, K. Munakata, S. Nakahira, J. Nishimura, G. A. de Nolfo, S. Okuno, J. F. Ormes, N. Ospina, S. Ozawa, L. Pacini, P. Papini, B. F. Rauch, S. B. Ricciarini, K. Sakai, T. Sakamoto, M. Sasaki, Y. Shimizu, A. Shiomi, P. Spillantini, F. Stolzi, S. Sugita, A. Sulaj, M. Takita, T. Tamura, T. Terasawa, S. Torii, Y. Tsunesada, Y. Uchihori, E. Vannuccini, J. P. Wefel, K. Yamaoka, S. Yanagita, A. Yoshida, K. Yoshida, and W. V. ZoberThe CALorimetric Electron Telescope (CALET) cosmic ray detector on the International Space Station (ISS) has been in operation since its launch in 2015. The main instrument, the CALorimeter (CAL), is monitoring the gamma ray sky from ~1 GeV up to ~10 TeV with a field-of-view of about 2 sr for more than three and a half years. In this paper, we describe the improvement on gamma ray analysis to reduce secondary gamma rays produced by interaction of cosmic rays with the ISS structures and the automated search system for transient gamma-ray events such as gamma ray bursts and flares of active galaxies, and set upper limits on gamma-ray emission from gravitational-wave event candidates reported by the LIGO/Virgo third observing run since 2019 April.8 pagesen-USThis work was written as part of one of the author's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law.Public Domain Mark 1.0http://creativecommons.org/publicdomain/mark/1.0/Text