Shimabara Earthquake and Volcano Observatory, Graduate School of Sciences, Kyushu University introduced the complete satellite-communications system into the earthquake prediction research observation network of the university in cooperation with the eight National Universities (Hokkaido University, Hirosaki University, Tohoku University, the University of Tokyo, Nagoya University, Kyoto University, Kochi University, and Kagoshima University).
This aims at "reinforcement of national earthquake observation data circulation", and "the advancement of temporary (emergency) earthquake observation.
By introduction of this system, the epoch-making earthquake observation system that was impossible in the former of acting as the collection and transmission of the waveform of all the earthquake observation points of national universities on real time using satellite communications was realized.
[The systems of Kyushu University] |The map of earthquake observation network having shown satellite communications|
|The collection of photographs of an observation point | The report in the newspaper |
*The seismic wave forms from the transmitting points of the 225 whole country are collected, and it transmits to the receiving points of the 24 whole country on real time.
*It transmits directly from the transmitting station installed in the observing point, and also by collecting it from an observation position after relay by the ground circuit and transmitting, finally national points (regular 250 point ＋temporary 100 point ＋ other organizations data) are collected by the satellite and it is transmitted.
*Reception of national data is possible on real time at national research bases and all the manned observation points.
*By 2 hop system of [transmitting station - > relay station - > receiving station], transmission and reception are possible with easy equipment.
*Data is efficiently transmitted by the packet system and resending of a lack packet is possible.
*Data conversion equipment of an extensive dynamic range (22 bits).
*Since it is not dependent on a ground network, it is hard to be influenced of a disaster.
*In the mountains and a detached island can also be used, without being restrained by distance.
*In the case of urgent, a temporary observation network can also be developed immediately.
*Data is receivable with broadcast satellite in many research bases.
*The common use of data can be carried out in the whole country on real time.
*The obstacle of 1 observation center can be backed up in other centers.
*Since advanced temporary observation can be developed quickly and easily, scrutinization research of an important area is promoted.
*Extensive researchers can use national temporary observation data and regular observation data on real time.
*It is enabled to pursue the seismic activity by data processing of the wide area without the "joint" of the observation network of each university.
*The project which collects data of a national scale can be realized easily.
| The satellite in use | JCSAT-3 (geostationary orbit of East longitude 128 of the equatorial sky) |
| The frequency band in use | Ku band(14GHz band, 12GHz band) |
| Service area | The whole Japan (Ogasawara is included) |
| Classification | Function | The number of stations | Installation place |
| The main relays station | The function for surveiling and controlling relay | 1 | S-NET satellite-communications center,Shinto-mura,Gunma-ken |
| The sub relays station | Backup of the main relays station, and a transmission-and-reception function | 1 | Earthquake Research Institute, the University of Tokyo |
| Transmission-and -reception station (VSAT) | Transmission function of data collection system. Reception function of data transmission system | 24 | Faculty of Science,Kyushu University (Fukuoka
city), Shimabara Earthquake and Volcano Observatory (Shimabara city). Other bases for the observations and researches. |
| Transmitting station (VSAT) | Transmission function of data collection system | 200 |
9 points for observing earthquakes of Kyushu University. 5 points for temporary observation of Kyushu University. Other bases and observation points for earthquakes. |
| System | Function | Course | Speed of information | The number of circuits |
| Data collection system | Collection of data | Transmitting station - > Relay station | 9.6~512kbps | 225 |
| Data transmission system | Transmission of data | Relay station - > Receiving station | 6.144Mbps | 1 |
| Data broadcast system | Control of observation equipment | Relay station - > Transmitting station | 9.6kbps | 1 |
| LAN system | LAN combines with IP | Between a transmission-and-reception station and a sub-relay station | 16kbps | 6 |
| Telephone system | Digital voice communication | Between a relay station and VSAT | 1 | |
| Common control line | Control of VSAT | Between a relay station and VSAT |