Current status of data center for cosmic rays based on KCDC

We present a current status of data center based on KCDC (KASCADE Cosmic Ray Data Centre), which was originally designed for providing an open access to the events measured and analyzed by KASCADE-Grande, a cosmic-ray experiment located in KIT, Karlsruhe. In the frame of the German- Russian Astroparticle Data Life Cycle Initiative we extend KCDC in order to provide an access to different cosmic-ray experiments and make possible aggregation and joint querying of heterogeneous air-shower data. In the present talk we discuss the description of data and metadata structures, implementation of data querying and merging, and first results on including data of experiments located in Tunka, Russia, in this common data center.