© GMV S.A., 2004 Property of GMV S.A. All rights reserved 2004/05/13 XML in CCSDS CCSDS Spring Meeting - Montreal Fran Martínez GMVSA 4081/04

2004/05/13 Page 2 Contents  Introduction to XML Description Pros and cons XML tools  OrbitML  ODM to XML (XODM) conversion Requirements and description Tool architecture Conclusions  Coming developments Tracking Attitude

© GMV S.A., 2004 Property of GMV S.A. All rights reserved 2004/05/13 Introduction to XML

2004/05/13 Page 4 Introduction to XML  eXtensible Mark-up Language  Implementation Tags : … Attributes :  Used for data representation Hierarchy Structure Qualification No format  Definition and verification DTD Schema

2004/05/13 Page 5 Introduction to XML  Hierarchy T00:00:

2004/05/13 Page 6 Introduction to XML  Structure T09:30:47-05: T09:30:47-05:00 String … T09:30:47-05:00 String

2004/05/13 Page 7 Introduction to XML  Qualification T00:00:

2004/05/13 Page 8 Introduction to XML  No format T00:00: T00:00: X = Y = Z = X_DOT = Y_DOT = Z_DOT =

2004/05/13 Page 9 Introduction to XML  Advantages Data structuring and organisation Extended in many fields  Generic tools  Innovative developments Generalised validation mechanisms Easy data transport with qualifiers Object orientation  Disadvantages Storage overhead Not human readable format

2004/05/13 Page 10 Introduction to XML  DTD Document structure Defines items and sequences Validation of syntax only <!ATTLIST stateVector frame CDATA #REQUIRED > <!ATTLIST time scale CDATA #REQUIRED format CDATA #REQUIRED comment CDATA #REQUIRED > <!ATTLIST position units CDATA #REQUIRED

2004/05/13 Page 11 Introduction to XML  Schema Defines document abstract structure Validation of semantics XML

2004/05/13 Page 12 Introduction to XML  Parsing tools xerces  DOM  SAX Implementation in C++, Java, Tcl, …  Visualisation tools Web navigators CSS XSLT  Validation tools DTD Schema

© GMV S.A., 2004 Property of GMV S.A. All rights reserved 2004/05/13 OrbitML

2004/05/13 Page 14 OrbitML  OrbitML Spacecraft Flight Dynamics Mark-up Language  Covers the whole s/c FD spectrum, including: Orbit and attitude determination & prediction Events generation Geodetic Applications Navigation  Handles related concepts Satellites, transponders, ground stations, physical models,... Object (Data) oriented approach

2004/05/13 Page 15 OrbitML  Design drivers Heritage from European FD packages … … improved consistency and portability Readability Extensibility to other space applications  OrbitML is a rich source of FD metadata Data model  hierarchy through XML  data typing through XML Schema …  … extended by OrbitML Data relationship  basic by XML and Schema …  … extended by OrbitML

© GMV S.A., 2004 Property of GMV S.A. All rights reserved 2004/05/13 ODM to XML Conversion Tool

2004/05/13 Page 17 ODM to XML Conversion Tool  Requirements ODM  XML notation  Analysis of ODM  Translation into XML (XODM)  XML structured data (data tree) Investigation of conversion tool  Approach Analysis of ODM data structures Definition of the XML approach  Existing tools  Existing supporting elements ( OrbitML ) Definition of the XODM structures Prototype demonstration

2004/05/13 Page 18 ODM to XML Conversion Tool  Tool generation rationale Isolate memory structures from data format representations (ODM & XODM) Perform validation of input files Common mapping to memory for both file representations  Data structure sharing  Bi-directional reading/writing Object oriented approach  XML/Schema  UML  C ++  Low level items reuse  Tools for scanning and parsing xerces-c/SAX for XODM lex + yacc for ODM

2004/05/13 Page 19 ODM to XML Conversion Tool

2004/05/13 Page 20 ODM to XML Conversion Tool OPM Data Structure

2004/05/13 Page 21 ODM to XML Conversion Tool OEM Data Structure

2004/05/13 Page 22 ODM to XML Conversion Tool ODM Parser Architecture

2004/05/13 Page 23 ODM to XML Conversion Tool Xerces/SAX Architecture Example

2004/05/13 Page 24 ODM to XML Conversion Tool  Tool generation conclusions Easy translation of data elements to XML Portable C++ (linux, windows, solaris) Full definition through Schema Proven reuse of OrbitML low level items  Schema  C++ data representation XODM integrated in OrbitML  Difficulties Format vs. Data structure Insertion of comments (ambiguities) ODM fixed units vs. XODM attributes

© GMV S.A., 2004 Property of GMV S.A. All rights reserved 2004/05/13 Coming Developments

2004/05/13 Page 26 Coming Developments  CCSDS Approach For already analysed elements (ODM) For items to be processed  Procedure Same as for ODM (?)  Existing formats/structures  Newly defined structures (directly in XML) Define procedure  Analysis  Definition of structures  Identification of reusable items  To come next Tracking Attitude

2004/05/13 Page 27 Coming Developments OrbitML observation file type structure

2004/05/13 Page 28 Coming Developments OrbitML attitude file type structure