Web Services for Satellite Emulation Development Kathy J. LiszkaAllen P. Holtz The University of AkronNASA Glenn Research Center

Motivation Support an emulation of space-based –Internet architectures –backbone network –formation clusters –Constellations Provide a web-based architecture for remote access and control of a multi-user, distributed system.

Complex Multi-satellite Emulation Scenarios

Internet NASA Satellite emulation test bed Experimenter Site

Data Format Need computational methods for efficient data: –access –sharing –information extraction SGML XML –simple –well-documented data –straightforward format –text

XML document creation Microsoft Word –create template with formats that map to your XML data –save in RTF format –RTF → XML converter applications with DOM parser JAVA API XSLT stylesheets

User input to the emulation reduce human error user-friendly interface automatically encode data into an XML document –well-formed –complete web-based

XSmiles An official W3C recommendation. Delivers a pure Java XML browser. Capable of displaying documents written in various XML languages. Supports: –XSL Transformations (XSLT) –XSL Formatting Objects (XSL FO) –Synchronised Multimedia Integration Language (SMIL) –XForms –XHTML –X3D –Scalable Vector Graphics (SVG) Allows rich multimedia content, such as video and audio, and streaming of it.

XForms emulation interface separates data from the web-page data content derived from forms is stored in XML (developer defined) format forwarded as a stream of Unicode bytes platform independent

XML File Scenario_one.xml

XForms XHTML XML Schema XSmiles XML

Emulation Scenario Satellite & ground stations Run-time control Orbital parameters Network routes Interface bandwidths Delay Bit error rates

XHTML element for basic XForms

XML Scenario Submission Internet CGI program

SOAP Simple Object Access Protocol XML-based protocol. Used for interoperability. Defines the use of XML and HTTP to access services, objects, and servers in a platform- independent manner.

Future Work XLINK –basis for graphs –providing a semantic representation of the objects defined in the form and their relationship to each other SVG –Language for describing two-dimensional graphics in XML. –Can be interactive and dynamic. –Animations can be defined and triggered either declaratively or scripted. Multimedia streaming content

XForms XLINK SVG Streaming Multimedia Internet