CALET Gamma-ray Burst Monitor observations

The CALET Gamma-ray Burst Monitor (CGBM) is the secondary scientific instrument of the CALET mission, continuously operating on board of the International Space Station (ISS) since October 2015.The CGBM consists of 2 Hard X-ray Monitors (HXMs) and one Soft Gamma-ray Monitor (SGM), utilizing different scintillators, LaBr3(Ce) and BGO respectively. The primary goal of CGBM is to observe a wide variety of gamma-ray bursts and other X/gamma-ray transients with fine temporal resolution (up to 62.5 us around triggers), broad spectral range (7 keV - 20 MeV) and wide field of view. By combining the data of CGBM and CALET primary instrument, Calorimeter (CAL), the energy coverage is extended to the GeV - TeV range.The CGBM has been detecting GRBs with an average rate of 3 per month, as expected from pre-launch estimation. CALET also takes part in the electromagnetic follow-up of gravitational wave (GW) observations made by LVC collaboration, by investigating the existence of possible X-ray and gamma-ray counterparts.We will report on CGBM in-orbit operation, performances, observations of GRBs and search for GW counterpa