At the core of any empirical trapped radiation model is a database containing energetic particle observations. The usefulness of such a database and the performance of the resulting models depend on the database flexibility to respond to queries based on differing magnetospheric conditions, and the ability to locate, select, retrieve and analyze the relevant particle data. Current empirical trapped radiation models, such as the NASA AE-8 and AP-8 models, are essentially flux lookup tables on ( E; B/ B 0, L) grids based on processed data. Such lookup tables are inherently static, non-updateable, and non-extensible. Consequently, the models constructed from them would have limited performance. As an initial effort to construct a new generation of empirical trapped radiation models, a new magnetospheric state-based trapped radiation database is being constructed in order to overcome existing model limitations. We have adopted an object-oriented database design to accommodate the complex and dynamic space radiation environment. The technique encapsulates the particle data, ancillary data, and metadata into abstract objects in a common framework to handle heterogeneous data sources. The new database structure will allow users to query the database using combinations of geophysical, temporal and spatial parameters. In this paper, we will focus on the implementation issues that arise in integrating heterogeneous data sets. To mitigate against early obsolescence when updated or new data become available, the models’ underlying database must be updateable and extensible. In addition, to ensure high model performance, the database must be parameterizeable, so that the selection of data from the database for analysis or modeling can vary with magnetospheric conditions or states that vary with solar wind and IMF driving conditions and geomagnetic responses (see Fung, S. F. Recent development in the NASA trapped radiation models, in: Radiation Belts: Models and Standards, Geophys. Monogr. Ser., vol. 97, American Geophysical Union, Washington, DC, pp. 79–91, 1996). By following an object-oriented design, the new trapped-radiation database can be easily updated, extended and re-parameterized. Our effort in constructing a prototype particle radiation database will be applicable to the NASA Living With a Star Program.
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Mar 1, 2013
Li Yan + 1
Open Access