Leica Geosystems TruStory GNSS Observation of Volcanic Activities in Sakurajima

Objective Volcano monitoring to predict volcanic eruptions

Customer/Institution Geosurf Corporation Disaster Prevention Research Institute Kyoto University, Sakurajima Volcanological Observatory

Date Start August 1994

Location Kagoshima Prefecture, Japan

Sakurajima is a volcano on the permission, within a 2 km range island of Kyushu. It is located of the Minami-dake crater. on the southern edge of the Aira Caldera and erupts from The volcanic explosion in October the summit of Sakurajima. This 1955 (Showa 30) was the starting summit is split into three peaks point for volcanic eruption predictions known as the Kita-dake (the at the Disaster Prevention Research northern peak), the Naka-dake Institute, and transitive volcanic (the central peak) and the Minami- activities have been monitored dake (the southern peak). The attentively ever since. In June 1956 Project Summary volcano is located in close (Showa 31), observation of volcanic Instruments proximity to the densely popu- activity in the mountain summits Leica GMX902GG Receiver lated Kagoshima city area. It is was on a full-scale level and it was Leica GRX1200 Receiver very active and is known to be determined that the duration would Leica AX antenna the largest active volcano in be of a long-term continual nature. Leica AT502 antenna Japan. The crater at Sakurajima’s This prompted the necessity to Software Minami-dake summit erupted in consider the construction of a Leica GNSS Spider October 1955 (Showa 30). Since permanent observation facility. Geosurf RIP (developed by Geosurf then, the volcano has been The Sakurajima Volcanological Corporation) spewing volcanic products Observatory was inaugurated in Communication (volcanic gas, ashes, lapillus December 1960 (Showa 35) and Internet and cinders), and creating earth originally constructed as an auxiliary Challenge and rock avalanches, which facility to the Disaster Prevention Monitoring volcanic eruptions and continues to cause damage in Research Institute and was endorsed predicting volcanic eruptions by every direction. Because of this, by the Ministry of Education, Science, utilizing the GNSS system no person is allowed, without Sports and Culture. Emphasis is placed on seismic GPS + GLONASS reception observation and ground deformation - The latest version of Leica GNSS observation, both of which are Spider was installed on the conducted at the Sakurajima analysis software Volcanological Observatory. In - The implementation of GEOSURF order to capture a versatile picture RIP enabled confirmation of and reach a comprehensive under- positional data standing, additional observation - The enablement of GNSS content is made sequentially obser- receiver operation from remote GPS antenna at “Kurogami” site vation to attain diversified observation. areas (by Leica GNSS Spider) was In Spring 1994 (Heisei 6), a total accomplished Characteristics of the new GNSS of 18 dual frequency GPS Leica - Back-up of observed data through receiver model SR299E receivers were installed, the implementation of CF cards Leica Leica with 9 receivers at Kirishima on the newest receivers (Leica GRX1200 GMX902 GG

Volcano Station and 9 at the GRX1200) was performed in the GPS ü ü

Sakurajima Volcano Station. GPS event of problems with trans- GLONASS ü ü

Network Monitoring started in mission. Dual frequency ü ü

August of the same year. Electricity 4W 2W consumption Network System Coverage Leica SmartTrack ü ü Web interface ü ü

CF card ü ü

Leica GNSS Spider ü o connection

Monitoring system setup Improvements were made in longterm reliability and static observation, by implementing Leica Geosystems “SmartTrack” function. Also, the Network range is 70km x 300km web interface makes it possible to remotely control multiple receivers Network System Configuration by using one computer terminal, An upgrade of the GPS Network Locations of 9 observation stations eliminating the necessity to go to System began in 2005 (Heisei 17) in the Sakurajima network the observation station to modify and consisted of the latest in the receiver configuration. receiver and analysis software. Establishment of Observation Additionally, a CompactFlash card The GPS network revision resulted Stations is used as a backup function for in improvements in the positional The Leica GMX902 GG GNSS receivers the observation data. This is system, system reliability and were newly implemented and particularly beneficial in volcano system efficiency. installed in 2 brand new observation monitoring and observation, where - The implementation of the latest stations and the Leica GRX1200 circumstances do not necessarily GNSS receiver resulted in the was updated in the existing observati- guarantee the stability of transmitted GNSS Network System enabling on station. data. With 1 GB, the CF card can hold up to7 weeks’ worth of data. “GEOSURF RIP” is a system equipped is possible to attain the estimated The GMX902GG design is compact with a coordinate transformation pressure source positioning and and solid and is a GNSS receiver function and converts coordinated magma output volume from such that was exclusively developed for measurements taken by “Leica data, as well as other observations, monitoring purposes. GNSS Spider” using WGS84/ITRF which in turn lead to and enable into the local frame of reference volcanic eruption prediction. Observation Data and Analysis and it simultaneously performs “Leica GNSS Spider” and “GEOSURF noise elimination. RIP” are both installed on the same Additionally, “GEOSURF RIP” utilizes computer terminal for analysis of the interface which displays a observation data, which is then sent simple and graphic image of the to the Volcanological Observatory. horizontal position, height, and The main function of “Leica GNSS directional position on the monitor Spider” is positional analysis. screen. Horizontal displacement vector from Oct 2009 to Oct 2010 when Horizontal Variation reference station is SVOG Variation of the horizontal vector is a key element in the analysis of Conclusion volcanic observation. The recent update in the observing The following diagram displays system resulted in an improvement horizontal direction movements, of positional accuracy. from the past year. The displayed movements originate from the Main GUI of “Geosurf RIP” respective observation stations. It

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