H. Hashiguchi1*, M. Shiotani1, M. Yamamoto1, A. Shinbori2 and T. Tsuda1
*1Research Institute for Sustainable Humanosphere (RISH), Kyoto University, Japan
2Institute for Space–Earth Environmental Research (ISEE), Nagoya University, Japan


The MU (Middle and Upper atmosphere) radar installed in Shigaraki, Shiga, Japan (34.85N, 136.10N) is one of the most powerful and multi-functional VHF-band atmospheric radar with an active phased array system consisted of 475 antenna elements (Fukao et al., 1985a, b). The MU radar has a monostatic circular antenna with a diameter of 103 m, which can be divided to 25 independent subarrays. The MU radar has been operated since 1984. Aiming at monitoring detailed structure inside the radar range volume, the MU radar imaging observation system has installed in 2004 (Hassenpflug et al., 2008). We can switch the operational frequency between 46.0 MHz to 47.0 MHz in every Inter-Pulse Period (IPP). The receiver system is also upgraded to 29-channel digital receivers. The received signal of each sub-array can be independently detected, and combined in the digital processing. This new feature enables us the multifunctional observation of Coherent Radar Imaging (CRI) and Frequency domain Interferometric Imaging (FII) techniques. The databases for tropospheric and lower stratospheric observations (altitude: 2-25 km), mesospheric observations (60-90 km), ionospheric observations (200-600 km), and meteor trail observations (80-100 km) are published in

The Equatorial Atmosphere Radar (EAR) is a VHF-band atmospheric radar located in Kototabang (100.32E, 0.20S), West Sumatra, Indonesia (Fukao et al., 2003). It is operated by collaboration between the Research Institute for Sustainable Humanosphere (RISH), Kyoto University and National Institute of Aeronautics and Space of Indonesia (LAPAN) since 2001. The EAR is a large monostatic radar which operates at 47.0 MHz with peak output power of 100 kW which is 1/10 of the MU radar. The EAR uses a quasi-circular antenna array, approximately 110 m in diameter, which consists of 560 three-element Yagi antennas. Each antenna is driven by a solid-state transmitter-receiver module. This system configuration allows the antenna beam to be steered electronically up to 5,000 times per second. The scientific objective of the EAR is to advance knowledge of dynamical and electrodynamical coupling processes in the equatorial atmosphere from the near-surface region to the upper atmosphere. The equatorial atmosphere over Indonesia is considered to play an important role in global change of the Earth's atmosphere. The databases for tropospheric and lower stratospheric observations (altitude: 2-20 km), and ionospheric field-aligned irregularity (FAI) observations (80-500 km) are published in and, respectively.

Various instruments (i.e., L-band lower troposphere radar, meteor wind radar, MF radar, lower thermosphere profiler radar, Rayleigh Raman lidar, etc.) have also been operated in the Shigaraki MU Observatory in Japan and in the Equatorial Atmosphere Observatory in Indonesia. These data as well as the MU radar and EAR data are provided through Inter-university Upper Atmosphere Global Observation NETwork (IUGONET; They correspond to Data Analysis Software SPEDAS/UDAS, which provides an integrated analysis platform for Solar-Terrestrial Physics.


Fukao, S., T. Sato, T. Tsuda, S. Kato, K. Wakasugi, and T. Makihira (1985a), The MU radar with an active phased array system, 1. Antenna and power amplifiers, Radio Sci., 20, 1155-1168.

Fukao, S., T. Tsuda, T. Sato, S. Kato, K. Wakasugi, and T. Makihira (1985b), The MU radar with an active phased array system, 2. In-house equipment, Radio Sci., 20, 1169-1176.

Fukao, S., H. Hashiguchi, M. Yamamoto, T. Tsuda, T. Nakamura (2003), M.K. Yamamoto, T. Sato, M. Hagio, and Y. Yabugaki, Equatorial Atmosphere Radar (EAR): System description and first results, Radio Sci., 38, 1053, doi:10.1029/2002RS002767.

Hassenpflug, G., M. Yamamoto, H. Luce, and S. Fukao (2008), Description and demonstration of the new Middle and Upper atmosphere Radar imaging system: 1-D, 2-D, and 3-D imaging of troposphere and stratosphere, Radio Sci., 43, doi:10.1029/2006RS003503.