Quarter Century of Nobeyama Radioheliograph and Its Contribution to Space Weather Research

Nobeyama Radioheliograph (NoRH) is a radio interferometer specially designed to observe the full Sun. NoRH started its scientific operation in 1992 with a single frequency of 17 GHz and then, 34 GHz capability was added in 1995. NoRH consists of eighty-four antennas with a diameter of 80 cm, installed along a T-shape baseline (North - South: 250 m, East - West: 500 m). The spatial resolution is about 10 arcseconds and 5 arcseconds in 17 GHz and 34 GHz, respectively. The time resolution is 1 second in quiet time and 0.1 second during a solar flare.