Nobeyama Radio Polarimeters (NoRP) are observing the Sun
with multiple frequencies in the microwave range.
It is capable to obtain the total coming flux and the
circular-polarization degree.
The system of 17 GHz is routinely working since 1978, that of 35 GHz since 1983,
and that of 80 GHz since 1984. The systems of 1, 2, 3.75, and 9.4 GHz
were working at Toyokawa observatory of the
Research Institute of Atmospherics, Nagoya University since around 1979.
They were moved to Nobeyama in Apr 1994 and has been working since then.
Nakajima et al. "The Radiometer and Polarimeters at 80, 35, and 17 GHz
for Solar Observations at Nobeyama", PASJ, 37, 163 (1985)
Torii et al. "Full-Automatic Radiopolarimeters for Solar Patrol at
Microwave Frequencies", Proc. of the Res. Inst. of Atmospherics,
Nagoya Univ., 26, 129 (1979)
Shibasaki et al. "Solar Radio Data Acquisition and Communication System
(SORDACS) of Toyokawa Observatory",
Proc. of the Res. Inst. of Atmospherics,
Nagoya Univ., 26, 117 (1979)
