A Portal Service of Earth Observation Data via Google Earth

Eizen Kimura ¹, Ken T. Murata ², Satoshi Ishikura ³, Ryosuke Nakamura ⁴, Satoru Suzuki ⁵, Hisato Iwata ⁵, Masafumi Hirahara ⁶, Iku Shinohara ⁷, Yasumasa Kasaba ⁷, Takuya Kubo <sup>3

1</sup>Department of Medical Informatics Social Medicine and Medical Informatics Medical School of Ehime University, Shitsukawa, Toon, Ehime 791-02, Japan
²Center for Information Technology, Ehime University, 3 Bunkyo-cho Matsuyama, Ehime 790-8577, Japan
³Graduate School of Science and Engineering, Ehime University, 3 Bunkyo-cho Matsuyama, Ehime 790-8577, Japan
⁴Grid Technology Research Center, National Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, Japan
⁵Center for Marine Environmental Studies, Ehime University, 3 Bunkyo-cho Matsuyama, Ehime 790-8577, Japan
⁶Department of Physics, Rikkyo University, 3-34-1 Nishi-ikebukuro, Toyoshima-ku, Tokyo 171-8501, Japan
⁷Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Yuyadai 3-1-1, Sagamihara, Kanagawa 229-8510, Japan

Due to the developments of large-scale Earth observation technologies, including spacecraft observations, many observation data are being yielded everyday. We need to compare and analyze many observation data to understand the global mechanism of the Earth as a complex system. The initial step to the comparison is to visualize these plenty of observation data on a system. In the present study, we propose a portal service of the Earth observation data which works on the Google Earth. The schematic design of the system is shown in the Figure below. The portal server makes a data list after collection of data information from local Web servers, which are distributed over the Internet and independently managed at each organization. The users then make a choice of data from the data list. After the selection of data, the users send a request message with data name, start time and end time to the portal server. The portal server collects KML files corresponding to the selected data and period from the local Web service servers. Note that the KML is one of the XML formats designed for the Google Earth. Since management of each local Web service server is independent, the total procedure between the local servers and the portal server must be simple. In the present system, the users get a set of KML files in the following manner; The local Web service servers simply prepare two methods: GetDataList() and GetKML(DataName, StartTime, EndTime). The portal Web service server first uses the GetDataList method to get lists and information of the data. The users make a choice of data from the data list exhibited on the portal server. The portal server then gets KML files from local servers with assigning data name and periods. The portal server finally returns the users a set of KML files. It should be noted that the Google Earth provides an environment to visualize two or more KML files simultaneously on one viewer.