H-alpha flare patrol observations at Mitaka were performed visually by a spectrohelioscope from 1948 to 1965. Then in 1957 in the IGY period a monochromatic heliograph (made in France) was installed. Photographic observations had been continued up to 1992, when a new system based on a video camera and a computer was introduced. The current observing system is made of a refractive telescope of 4.5cm aperture, a birefringent filter made by Halle, Germany, and a CCD camera. Digitized H-alpha images of the solar disk are obtained every one minute. If a flare is detected, a one-second cadence data recording starts automatically. The system was initially put on top of the monochromatic heliograph, but now it is installed on the new sunspot telescope.

Reference: Fulldisk