Overview of international experiment campaign with small optical transponder (SOTA)

NICT initiated R&D effort of Small Optical TrAnsponder (SOTA) for LEO satellites to demonstrate the laser communication via satellite-to-ground atmospheric path links. SOTA is the payload on a 50-kg class microsatellite called Space Optical Communication Research Advanced Technology Satellite (SOCRATES), launched on 24th of May, 2014. Several international partners were interested in joint collaboration and NICT has initiated the international experiment campaign using SOTA with other agencies to perform laser communication experiments between SOTA and different international Optical Ground Stations (OGSs). In this paper, we describe the interface and link establishment protocol that had to be considered in the different OGS and the preliminary results in the international experiment campaign using SOTA.