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The Old World Meets the New:The Old World Meets the New:Utilizing Java Technology to Revitalize and Utilizing Java Technology to Revitalize and Enhance NASA Scientific Legacy CodeEnhance NASA Scientific Legacy Code
Michael D. ElderFurman University
Hayden S. Porter, Advisor
Purpose of ResearchPurpose of Research
Analyze the first of several NASA Scientific Legacy applications designed to support the TIMED satellite mission
Design an architecture to allow these applications to utilize modern graphical methods of data representation, including animations
Implement and test architecture for Proof of Concept
Legacy Applications BackgroundLegacy Applications Background
Model global atmospheric circulation for several gas species
Support data analysis for NASA’s upcoming TIMED Satellite Mission
Written in FORTRAN Require proprietary graphic
visualization software
Limitations of the existing Limitations of the existing TIMED Legacy ApplicationsTIMED Legacy Applications Platform dependent User interface confined to a console window
or VAX compatible menu display No network access
– TIMED and other network data sources will be required
No Graphical Virtual Machine (GVM)– Precludes development of interactive, platform-
independent, three-dimensional visualizations or animations
Options for ModernizationOptions for Modernization
Rewrite the original application and its graphical visualizations in a modern language
Design platform-independent application wrapper abstraction– “preserves legacy code by encapsulating
application elements in an object oriented shell that can be used in client-server systems” [Lyons95]
– Allows original legacy application to interact with modern environments with little or no modification
– Use of existing FORTRAN code as an efficient compute server
Summarized object designSummarized object design
XML Encapsulation of Legacy DataXML Encapsulation of Legacy Data
XML tags define content of legacy system output
Clients define the visualization mechanism of the tagged data
Multiple clients could be plugged in without modification of server
Why use Java for implementation? Why use Java for implementation?
Distributed Application Wrapper Architecture through Remote Method Invocation (RMI)
Java-based control of original application by executing native processes– Full access to STDIN, STDOUT, and STDERR
Powerful standard libraryPlatform Independent by nature
Graphical WizardsGraphical Wizards
Are triggered by XML tags from serverExample wizards allow users to define
source-intensity functions for the global circulation model found in the NASA legacy application
Demonstrate a hierarchy of interactivity which can be seamlessly integrated with original application– From drawing two dimensional time and
latitude dependencies to full three dimensional creation of source inputs
Architecture AdvantagesArchitecture Advantages
Runs locally for high-speed communication of graphical visualization or animation data or remotely for application functions which do not require a high bandwidth
Permits legacy applications that cannot be ported to other platforms to run on their original platform using a Distributed Application Wrapper
Architecture AdvantagesArchitecture Advantages
Tagged Content– Pre-processing and preparation of legacy
output by Server component– Client watches for tags and reacts accordingly– Seamless extension of program functionality
Interactive, three-dimensional, data visualizations and animation can be defined by the client for the tagged content relayed from the server
ConclusionConclusion
This architecture can be readily applied to a variety of legacy systems in different application domains
Implementation of this architecture for the NASA global circulation model application has proven very effective
Extensions– Examine Context-sensitive Intelligent Agents as
clients to further enhance the adaptability of this architecture for legacy systems
Acknowledgments Acknowledgments
Dr. Hayden S. Porter, Professor of Computer Science, Furman University
Dr. Hans Mayr and Dr. John Mengel, Goddard Space Flight Center
Supported, in part, by the Furman Advantage Summer Research Program and a grant from NASA.
More InformationMore Information
Presentations and papers on this research can be found at the following web address:http://michael_elder.home.mindspring.com/research
Contact the author of this presentation for more information:[email protected]
Michael D. ElderMichael D. [email protected]@acm.org
Furman UniversityFurman University
Dr. Hayden S. Porter, Dr. Hayden S. Porter, AdvisorAdvisor
