Report on the Activity of Commission G

(15 July 2005)



1.      Development of Ionospheric observation facilities


Ha Noi Institute of Geophysics, Vietnamese Academy of Science and Technology, Vietnam and National Institute of Information and Communications Technology (NICT) of Japan agreed about plans for installation of an ionosonde in Bac Lieu Province, 300 km south of Ho Chi Minh City close to the magnetic equator (1.66 deg. magnetic latitude). Bac Lieu station will be the fourth ionosonde station of SEALION (Southeast Asia Low latitude Ionospheric Network). NICT is constructing SEALION for the purpose of forecasting onsets of equatorial plasma bubbles and equatorial anomaly development, which is important for the operation of GPS navigation system.


"Coupling Processes in the Equatorial Region (CPEA)" is a research project funded by the Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT) as a Grant-in-Aid for Scientific Research on Priority Areas. Since the beginning of the project in 2001, we have accumulated a variety of observation equipments at the Equatorial Atmosphere Radar (EAR) site in West Sumatra, Indonesia. The installation of the whole equipments finishes in July 2005. By April 2005, Prof. C. Nagasawa of Tokyo Metropolitan University installed a Rayleigh lidar and a Fe+/Na lidar. The Rayleigh lidar is capable of observing atmospheric temperature and density up to the altitude of 80 km. The Fe+/Na lidar is a resonant-scatter lidar to measure ionized iron and atomic-sodium layers at 90-100 km heights. Prof. T. Ogawa, Solar-Terrestrial Environmental Laboratory, Nagoya University, recently conducted the installation of the last equipment in the EAR site. That is a VHF radar to monitor continuously backscattering echoes from meter-scale irregularities such like equatorial plasma bubbles and sporadic E. With these instruments of the CPEA, the EAR site became the most completed observation site for the dynamics of the atmosphere and the ionosphere right at the geographic equator.


A small satellite plan was proposed to Japan Aerospace Exploration Agency (JAXA) by Mesosphere-Thermosphere-Ionosphere (MTI) satellite working group of Japan in January 2005. The satellite aims to observe density structures of the MTI-region at low- and mid-latitudes using the airglow emission from the Earthfs upper atmosphere. The satellite is planned to fly in the geo-transfer orbit, and detects the global distribution of airglows when it is near the apogee. In-situ measurement and limb observation is carried out when it is near the perigee. The visible and infrared imager (VISI) and far ultraviolet imager (FUVI) observe the airglow distribution with high spatial resolution. This satellite observation is expected to connect the fragmented information on the MTI phenomena, such as atmospheric gravity waves, plasma bubbles, and traveling ionospheric disturbances. Extreme ultraviolet imager (EUVI) observes He+ distribution in the plasmasphere with 30.4nm resonance line emission. The combination of the ionospheric and plasmaspheric observation would be a strong tool to characterize, mitigate, and predict ionospheric effects on the global navigation satellite systems, such as GPS. The mission period is proposed for one year during the next solar maximum.


2.      Observation Campaign


CPEA plans to conduct two international observation campaigns during 2004-2005. The first campaign, CPEA-I, was successfully conducted in March-May 2004. The second campaign, CPEA-II, is planned in the period from September to December 2005. The core period of the experiment is one month from middle November to middle December. In September-October 2005, we conduct radar and lidar observations of equatorial plasma bubbles. These CPEA campaigns are endorsed by CAWSES (Climate and Weather of the Sun-Earth System) under SCOSTEP (The Scientific Committee On Solar-TErrestrial Physics). (Contact of CPEA-II is Dr. M. Yamamoto, Kyoto University, at


3.      Data Analyses and Services


NICT started to provide near-real time ionosheric total electron content (TEC) data over Japan using GEONET (GPS Earth Observation Network) data, as a part of Space Weather data services.

TEC data are important for monitoring onsets of ionosheric storms in summer season as intense sporadic E traces often blanket the F-region trace.


4.      Coming Workshops


(1)  IAGA Scientific Assembly, in Toulouse, 18-29 July 2005,

(2)  URSI General Assembly, in New Delhi, India, 23-29 October 2005,

During URSI General Assembly cited above, a General Lecture and an intercommission session on Solar Power Satellite (SPS) are arranged as below. Dr. Michael Rietveld of EISCAT will also give a talk entitled, "Interactions between microwave power transmissions from a solar power station and the ionosphere-atmosphere system" based on the recommendation of Commission G.

U1 - GENERAL LECTURE 1 (Monday 24/10/2005 14:00-15:20)

gSolar Power Satellite (SPS) for Sustainable Clean Energy Humanosphereh by Prof. Hiroshi Matsumoto

HX - INTERCOMMISSION SESSION - Solar power satellites (SPS) (I,C,P)

(Tuesday 25/10/2005 14:00-16:20) Session subjects include: passive and active microwave devices, antenna and rectenna, huge antenna arrays, retrodirective systems, antennas in plasma, self calibration, compatibility with telecommunications and radio astronomy, radio frequency interference and electromagnetic compatibility (RFI and EMC), the interaction of heavy ions ejected from the electric spacecraft propulsion engine. (Conveners: H.Kozo Hashimoto, Japan: and D. Tatsuo Itoh, USA:


(Prepared by T. Maruyama and M. Yamamoto)