High-speed Hα camera and the real-time image processing system for solar observations

We have developed a new digital imaging system for the Halpha imager of the Solar Flare Telescope at Mitaka, NAOJ, for high-cadence observations of solar flares. To resolve individual spikes (elementary bursts) of impulsive solar flares requires a time resolution within 1 s and a spatial resolution of about 1", and the high-speed Halpha camera realized them. Such high-resolution observations produce huge amount of data, and it has been the major difficulty to construct a high-cadence system. Generally the amount of data from solar optical observations is huge, because they are multi-dimensional (in space/time/wavelength/polarization status). Efficient real-time processing of observational data is essentially important to extract meaningful information from the raw data. Recent advances in computer technology have made possible to handle vast data with a small computer. Therefore, firstly we have developed a PC-based flexible real-time image processing system, which is applicable to various real-time data processings required for solar optical observations. The high-speed Halpha camera is developed based on this system. In this paper, the real-time image processing system and the high-speed Halpha camera system are described as well as the actual operation of the Halpha camera.