DAGIK : A DATA-SHOWCASE SYSTEM FOR THE GEOSPACE

We propose to establish “data-showcase” system to display the various geophysical data in one frame. Data-showcase is a system not to provide data but to show various types of the geophysical data in intuitable way. The newly developed Dagik, Daily geospace data in kml, is the first data-showcase system for the geospace data. It contains several types of data by ground-based and satellite measurements in addition to numerical models. We expect Dagik would make the combination and comparison of the geospace data easier, and foster new inter-disciplinary scientific researches.


DATA-SHOWCASE SYSTEM
We propose to establish data-showcase system to enhance the data sharing of the geophysics.The data-showcase system is designed to display plots of various geophysical data in one frame to show their outline.Location and time are the essential information of the geophysical data.Therefore, the data-showcase system should present the data in four dimensions, three dimensions in space and one dimension in time.In the data-showcase system, various data can be plotted in one frame to compare each other.The plots contain the information of the data.It can allow users to access the database of the data to download and study in detail.Thus, the data-showcase system can play a role as a portal of the geophysical data.Users can browse various data with the data-showcase system.If they are interested in a certain data, they can access the data following the information in the data-showcase system through WWW.
The data-showcase system is a system to browse the geophysical data plots to compare each other.The required Data Science Journal, Volume 8, 30 March 2009 functions for the data-showcase system are as follows: 1) Four-dimensional data presentation capability.
2) Scalability in time and space.
The uniqueness of the geophysical data is that they are closely connected with time and space.To combine data that were observed in various locations and time, four-dimensional plot capability is necessary for the intuitable data presentation.The temporal and spatial scales of the data are also variable.Some data have higher sampling rates than 1Hz, and some data consist of daily values.To plot various geophysical data, the data-showcase system should be scalable in time and space.Finally, to display various types of data, network capability is necessary.It is impossible to store all the data in a local computer, and it is efficient to download the data through fast networks.

DAGIK
We developed a data-showcase system for the geospace data.That is called Dagik (Daily Geospace data in Kml) (http://www-step.kugi.kyoto-u.ac.jp/dagik/).Dagik data plots are written in KML (Keynote Markup Language), and browsed with Google Earth.The reason to use KML as its plot format and Google Earth as its browser is that they satisfy the required three functions for the data-showcase system discussed above.Making four-dimensional plots of various types of geophysical data on Google Earth with KML is simple and easy.One of the current problems of Google Earth as a data-showcase browser is that its plot area is limited from the Earth's surface to 11 Re.  3) The user can select preferred dates from the "side-bar" window of the Google Earth to display.4) For the selected date, the data list file will be downloaded from the Dagik server, and displayed in the sidebar window.5) User can select the data type from the data list, 6) and the KML/KMZ plot files will be downloaded from the Dagik server or the other KML/KMZ server to be displayed on Google Earth.KMZ is a compressed file format of KML.
There are several databases that provide their data plots in KML/KMZ format for Dagik.Some of these databases will be introduced in the following section.
Dagik is a system using the distributed database system connected by the Internet.The plot files are stored and provided by several the KML/KMZ servers.Most of the KML/KMZ are operated on the WWW-based databases of the data holder.It, therefore, is relatively easy to increase the number of data on Dagik with the collaboration of the data holders who already operates the WWW-based databases.It is important to increase the number of data in Dagik.

Figure 1 .
Figure 1.Example of data display by Dagik.Data list is displayed in the "side bar" window on the left.Data displayed in the right panel for 13:24UT on April 19, 2002 are solar wind, geomagnetic indices, EISCAT radar, GPS total electron content, geomagnetic field variations, ion density by the DMSP satellite, and so on.

Figure 1 Figure 2 .
Figure 1 shows an example of the data display by Dagik.Data shown in the right panel is the solar wind data, the geomagnetic indices Dst and AE, the EISCAT radar data, GPS total electron content, geomagnetic field variations by ground-based magnetometers, the ion density by the DMSP satellite, the geomagnetic field by the GOES satellite, and the geographic and geomagnetic coordinates.The time of the data was at 13:24UT on April 19, 2002.Data list is displayed in the "side bar" window on the left hand side.Users can select the date and data type from the "side bar" window to display the data plot.The data plots written in KML are superimposed to compare the location and time of the data.The data that does not have location information such as indices are displayed as a two-dimensional plot on the panel.The various types of data are plotted in one frame, and make themselves easy to compare with each other.