Full-disk solar chromospheric spectroheliograms around Ca II K absorption line obtained with the Coelostat spectroheliograph and photographic plates at Kwasan Observatory and Ikoma Observatory. Though these data-files were all digitized from analogue data, they are not performed any corrections nor calibrations. Therefore, they are not open on the web. If you want to investigate these non-calibrated data, please contact the person in charge.

Reference: FullDisk