Developing Near Real Time Tec Computation System Fromgps Observation For Improving Spatial Resolution Observation Of Ionosphere Overindonesia

Ionosphere above Indonesian stretches about 5,120 km toward longitude, and about 1,760 km toward latitude. Assuming that the spatial variation of the ionosphere has a 500 km in longitude direction, and 250 km in latitude direction, by ignoring difficulties of GPS observation from see surface, the required minimum of GPS station in Indonesia is about 72 stations for ionosphere observations with enough spatial resolution. National Institute of Aeronautics and Space (LAPAN) has only several stations that available for GPS receiver site, so that ionosphere observations independently by LAPAN does not meet user needs of spatial resolution of ionosphere observation by using GPS receiver. Hence GPS station operated by other institutions is needed for ionosphere observation. But the GPS TEC data is not yet available at institutions other than LAPAN where most of the GPS data is stored in rinex format. Therefore, it needs a strategy for GPS data management from other institutions so it can be used for ionosphere observations nationally. As a first step, the near real time TEC computing systems has been developed from GPS data established by Geospatial Information Agency (GIA). This paper discusses the GPS-based TEC computing system and its potential application and development to meet the needs of ionosphere data in spatial resolution.