CPICPICPI NEXT GENERATION TRANSPORT PHENOMENOLOGY MODEL

Harold Knight Douglas Strickland

J. Scott Evans

Computational Physics, Inc.Springfield, VA

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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)

CPICPICPIRELEVANCE 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

CPICPICPI 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supported with multiple users having concurrent, real-time access to algorithms, modeling inputs, and results that have been archived from prior executions of the tool

CPICPICPI 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

CPICPICPI 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

CPICPICPI 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)

CPICPICPI WORK COMPLETED SINCE OCT 2002 WORKSHOP – cont.

CPICPICPI WORK COMPLETED SINCE OCT 2002 WORKSHOP – cont.

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• 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?)

WORK TO BE COMPLETED

CPICPICPI

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)

CPICPICPICOMPONENT 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

CPICPICPIEXAMPLES OF USE CASES

Main Use Case Diagram Execute TPMT Use Case Diagram

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• Top-level PPMT design

SOFTWARE ARCHITECTURE

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• Scattering phenomenology design

Software Architecture (cont.)

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• 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

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• 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.

CORBA COMPONENT MODEL

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• 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

EJCCM

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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

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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.

CPICPICPI TIMED/GUVI AND NRLMSIS GLOBAL O/N2 ON 3/23/02 AND 3/24/02. DISTURBED COMPOSITION

ON 3/24 CAUSED BY GEOMAGNETIC STORM

CPICPICPI TIMED/GUVI-DERIVED QEUV OVER STRONG SOLAR ROTATION AND COMPARISON WITH SCALED SOHO/SEM

DATA. SOLAR FLARES PRODUCE FINE STRUCTURE

CPICPICPI TIMED/GUVI auroral image from the N2 LBHL FUV spectral channel

CPICPICPIAuroral emission from N2 (LBHL), emission ratios, and derived data products (electron precipitation [Eo and Q] and neutral composition [O density scaling factor fO])

CPICPICPI 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.

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AURORA