NoRH image

Nobeyama Radioheliograph

English / Japanese

Nobeyama Radioheliograph (NoRH) is a radio telescope dedicated to observe the Sun. "Helio" means the Sun, "graph" means an imaging telescope. It consists of 84 parabolic antennas with 80 cm diameter, sitting on lines of 490 m long in the east/west and of 220 m long in the north/south. Its construction took 2 years and cost 1.8 billion yen. The first observation was in April, 1992 and the daily 8-hours observation has been done since June, 1992.

Frequency 17GHz (Right and left circular polarization), 34GHz (only intensity)
Field of view Solar full disk
Spatial resolution 10 arcsec (17GHz), 5 arcsec (34GHz)
Temporal resolution 0.1 sec (Event), 1 sec (Steady)

As the NoRH is a radio interferometer, original data are sets of correlation values of all the combination of antennas. They correspond to the spatial Fourier components of the brightness distribution of the solar disk. In most cases, it is necessary to synthesize images from the original raw data.

To maximize the data use, we prepare images, indices and other related materials routinely and put them on our Web page. This Web page is to help the scientists in the world to look for interesting phenomena detected by the NoRH and to start the actual analysis using the original data set. Software for image synthesis and analyses are prepared. Image synthesis and analyses can be done remotely through the Internet. This data and images can also be used for science education. We are glad if our images are of any help in education at schools, universities, and public.


Nakajima et al. "The Nobeyama Radioheliograph", Proc. of the IEEE, 82, 705, (1994)
Takano et al., "An Upgrade of Nobeyama Radioheliograph to a Dual-Frequency (17 and 34 GHz) System" in "Coronal Physics from Radio and Space Observations, Lect. Notes Phys.", (Berlin: Springer-Verlag) 183 (1997)
"The Nobeyama Radioheliograph -- A Collection of Papers on Initial Results and Instrumentation", NRO Report 357 (1994)
"New Look at the Sun with Emphasis on Advanced Observations of Coronal Dynamics and Flares", Proc. of Kofu Symp. NRO Report 360 (1994)