NEXT GENERATION TRANSPORT PHENOMENOLOGY MODEL Harold Knight Douglas Strickland J. Scott Evans Computational Physics, Inc. Springfield, VA
INTRODUCTION Transport Phenomenology Modeling Tool (TPMT) • Electron and photon transport modeling and associated excitation processes • Internet accessible, graphical user interface • CORBA Component Model (CCM) architecture with coarse grain parallelization and distributed computing • Legacy FORTRAN models reengineered in Java • Embedded in more general Atmospheric Phenomenology Modeling Tool (APMT)
RELEVANCE TO NASA PROGRAMS Scientific and Applied Research • Remote sensing analysis – deriving energy inputs, neutral densities, temperatures, and electron densities from optical emissions • An example of an application – NASA’s TIMED mission, GUVI auroral and dayglow optical emissions data (currently using legacy models) • General planetary atmospheres
RELEVANCE TO NASA PROGRAMS – cont. Support of Technology Goals • TPMT based on Enterprise Java CORBA Component Model (EJCCM) • Component-based approach provides interoperability with other component architecture compliant systems (CCM, EJB) • Collaborative efforts supported with multiple users having concurrent, real-time access to algorithms, modeling inputs, and results that have been archived from prior executions of the tool
WORK COMPLETED PRIOR TO OCTOBER 2002 WORKSHOP • Produced extensive set of use case specifications. Key specifications are: • the conversion of the collision integral to a matrix representation • local solution for the photoelectron flux • transport solution for auroral electrons • energy and altitude gridding algorithms • parameterizing incident auroral electron energy distributions
WORK COMPLETED PRIOR TO OCT 2002 WORKSHOP – cont. • Domain model (functional requirements of the system obtained from an analysis of the use case model) • Construction phase • XML configuration files (e.g., cross section files) • Implementation of auroral electron transport solution and photoelectron solution in local approximation • Testing of implemented solutions
WORK COMPLETED SINCE OCT 2002 WORKSHOP • Completed port of existing architecture to Enterprise Java CORBA Component Model (EJCCM) providing: • Packaging and deployment to different hosts • Model output archival, object state persistence • Resonance-line photon transport solution: • Wrote a detailed specification • Implemented the model in Java, found processing time within a factor of 2 of FORTRAN • Tested the solution by comparing with the original FORTRAN REDISTER solution (see next 2 pages)
WORK TO BE COMPLETED • Finish code for photoelectron transport solution using Feautrier method and column emission rate calculations • Create wrappers for required pre-existing FORTRAN components that will not be implemented in Java • Create a graphical user interface (GUI) for: • Editing input parameters • Archiving results in a database • Browsing and exporting archived results (formats?)
IT ISSUES • Software Architecture • Software development approach • Transport phenomenology design • CORBA Component Model (CCM) • What is CORBA? • What is the CCM? • Enterprise Java CORBA Component Model (EJCCM)
COMPONENT AND OO DESIGN CONCEPTS • Unified Modeling Language (UML) • Physical Analysis Methodology (PAM) – application of rigorous physical analysis facilitates the difficult tasks of developing the basic flow of events in use case specification as well as object diagrams • PAM yields designs tailored for use in distributed, component-based architectures
Main Use Case Diagram Execute TPMT Use Case Diagram EXAMPLES OF USE CASES
SOFTWARE ARCHITECTURE • Top-level PPMT design
Software Architecture(cont.) • Scattering phenomenology design
CORBA • Common Object Request Broker Architecture • Maintained by the Object Management Group (OMG) • Object-oriented architecture • Open and vendor-independent • Supports heterogeneous platforms • Support heterogeneous programming languages • Provides standard communication protocols • Internet Inter-ORB Protocol (IIOP) • Provides standard definition language • Interface Definition Language (IDL)
CORBA COMPONENT MODEL • CORBA V3.0 formally adopted by OMG • Consists of interlocking conceptual pieces • Abstract Component Model • Packaging and Deployment Model • Container Model • Mapping to EJB • Integration Model for Persistence and Transactions. • Conceptual pieces enable a complete distributed enterprise server computing architecture.
EJCCM • Enterprise Java CORBA Component Model • Developed by CPI for NASA • Most advanced Java implementation of the CCM • Proving ground for refinement of CCM specification • Framework for APMT projects • Framework for $50M Missile Defense Agency Project • Released under open source license • http://www.ejccm.org
FUTURE APPLICATIONS All slides after this one describe remote sensing analysis done using legacy FORTRAN model (not TPMT). TPMT/APMT will provide new capabilities such as: • Parallel processing for faster computation • Internet access and collaboration • Secure mode • Improved model output archiving and database search • Large scale simulation for entire globe (mission planning and/or data analysis) • Capability for substituting components (plug-and-play capability), e.g. for comparing models and data
APPLICATIONS • Using legacy models now. (TPMT is not ready yet.) • Theoretical investigations and data analysis • Behavior of dayglow and aurora • Excitation processes • Remote sensing • Algorithm development • Deriving information about processes, the state of atmosphere and ionosphere, and characteristics of external energy sources (solar EUV and precipitating electrons) • Neutral density profiles • Exospheric temperature • Relative column abundances of neutral species (e.g., O/N2 in terrestrial applications) • QEUV (integrated measure of solar EUV energy flux shortward of 45 nm) • Ionospheric parameters (e.g., NmF2 and HmF2) • etc.
TIMED/GUVI AND NRLMSIS GLOBAL O/N2 ON 3/23/02 AND 3/24/02. DISTURBED COMPOSITION ON 3/24 CAUSED BY GEOMAGNETIC STORM
TIMED/GUVI-DERIVED QEUV OVER STRONG SOLAR ROTATION AND COMPARISON WITH SCALED SOHO/SEM DATA. SOLAR FLARES PRODUCE FINE STRUCTURE
Auroral emission from N2 (LBHL), emission ratios, and derived data products (electron precipitation [Eo and Q] and neutral composition [O density scaling factor fO])
REFERENCES TO DATA PRODUCT ILLUSTRATIONS • Strickland, D. J., R. R. Meier, R. L. Walterscheid, A. B. Christensen, L. J. Paxton, D. Morrison, S. K. Avery, J. D. Craven, G. Crowley, and C.I-Meng, Quiet-time seasonal behavior of the thermosphere seen in the far ultraviolet dayglow, J. Geophys. Res., accepted, 2003. • Strickland, D. J., J. L. Lean, R. R. Meier, A. B. Christensen, L. J. Paxton, D. Morrison, S. K. Avery, J. D. Craven, G. Crowley, C. I-Meng, R. L. Walterscheid, D. L. Judge, and D. McMullin, Solar EUV irradiance variability derived from the terrestrial dayglow, Geophys. Res. Lett., accepted, 2003. • Strickland, D. J., J. H. Hecht, M. Conde, and D. Morrison, Auroral remote sensing using coincident satellite and ground-based optical observations, to be submitted to J. Geophys. Res., 2003.