Trieste, May 19, 2008IVOA Interoperability meeting IPDA: a Standards Initiative for Building Compatible Archives Maria Teresa Capria INAF – IASF Rome, Italy International Planetary Data Alliance

Trieste, May 19, 2008IVOA Interoperability meeting About the Planetary Data System NASA’s official archive for Planetary Science Data –Missions are required to archive data with PDS Federation of nodes –Science discipline nodes provide scientific and data management expertise –Central engineering addresses PDS-wide software and standards Standard archiving processes and tools –diversity of data types but a homogeneous architecture for archives Scientific community in the U.S. decided in the eighties to setup a data system for planetary related data (ground-based, laboratory data, space data), the Planetary Data System (PDS)

Trieste, May 19, 2008IVOA Interoperability meeting Characteristics of the PDS Data Archive The PDS archives and makes available space-borne, ground-based, and laboratory experiment data from over 50 years of NASA-based exploration of comets, asteroids, moons, and planets. The archives include data products derived from a very wide range of measurements, e.g., imaging experiments, gravity and magnetic field and plasma measurements, altimetry data, and various spectroscopic observations. Planetary missions frequently have short or intermittent observing phases that result in limited accuracy of calibration and incomplete understanding of instrument stability and characteristics. Many of the data sets are unique in that the observations cannot be duplicated. The wide range of archival products and associated disciplines are fundamental reasons why PDS is organized as a federation serving various science communities. The future is likely to be as diverse, unpredictable, and challenging as the past - requiring innovative management and state-of-the-art technology within a stable yet robust archiving framework.

Trieste, May 19, 2008IVOA Interoperability meeting PDS Functions PDS serves the scientific community by assuring the availability of high quality and scientifically useful data products To accomplish these goals, PDS –works with Data Providers to Prepare Archival Quality Data Products –provides Access to Data from NASA and International Missions –delivers Data to the Scientific Community –establishes a Common Data Model and Data Dictionary for Planetary Data –sets Archival Standards –preserves the Data –assists Scientists in Accessing and Using Planetary Data –is responsive to a diverse community of users –facilitates Education and Public Outreach PDS Planetary Science Data Model

Trieste, May 19, 2008IVOA Interoperability meeting PDS as a System Primary distribution of data occurs online –Users either access PDS via a central portal or through discipline-specific interfaces –Data is managed online at PDS nodes PDS nodes have basic data sharing capabilities to access data from remote repositories at other PDS nodes PDS provides common tools to missions to support design and validation of PDS compliant archives As PDS evolves, it will be enhancing its system and standards to support increasing data volumes, diversity in data suppliers, and better mechanisms for data access 2001 Mars Odyssey

Trieste, May 19, 2008IVOA Interoperability meeting Background Scientific community in the U.S. decided in the eighties to setup a data system for planetary related data (ground-based, laboratory data, space data), the Planetary Data System (PDS) Scientific community in Europe got acquainted to the PDS-Standard, as most data originated from NASA missions; ESA adopted the PDS- Standard as the base standard for it’s archival system, the Planetary Science Archive (PSA) NASA/PDS and ESA/PSA have worked closely together to coordinate archiving activities for current missions (e.g., Huygens, Mars Express, Venus Express) –This has led to ESA PSA/NASA PDS collaborating on an international strategy for planetary science data archiving to: Give scientific communities world-wide access and services to data archives built from similar standards Reduce cost of archiving and distributing science data by collaborating and sharing standards Ensure reusability of science data across agency/mission/instrument boundaries Coordinate archiving processes and plans Improve and increase services offered

Trieste, May 19, 2008IVOA Interoperability meeting Background In 2005, the PSA and PDS initiated an effort to develop common interoperability standards for accessing and distributing data internationally from national planetary science archives; this includes –A protocol for finding, accessing and retrieving science products from across agency systems –Common semantics for discipline-specific queries The plan is that joint missions in the future will use the interoperability protocol rather than submitting and archiving data from another agency in a local system. Other space agencies need to setup similar archival systems, including standards, tools, services, etc in the coming years to serve ‘their’ scientific community –Co-operations make it necessary to minimize the differences between systems and standards, e.g. Rosetta (NASA,ESA), BepiColombo (ESA,JAXA), Chandrayaan (ISRO,ESA), … –Wish from archival systems to share lessons-learned –Avoid re-inventing the wheel - if not explicitly wanted World-wide scientific communities want to have standardized archival systems –They (often) do not care about Space Agency’s considerations –Demand for new, sophisticated services and tools –Concerns in accepting data standards fully controlled by sister agency SOLUTION: internationalize the planetary data archival efforts

Trieste, May 19, 2008IVOA Interoperability meeting International Planetary Data Alliance Mission Statement The International Planetary Data Alliance (IPDA) is a close association of partners with the aim of maintaining and continuously improving the quality and services to planetary science data from ground or space based instruments. The specific mission of the IPDA will be to facilitate global access and exchange of high quality scientific data products managed across international boundaries and organized by a set of governing data standards. In 2006, the International Planetary Data Alliance was established which includes participation from major space agencies around the world.

Trieste, May 19, 2008IVOA Interoperability meeting International Planetary Data Alliance Objectives The main objective of IPDA is the enhancement of the research activities in the worldwide planetary community. The IPDA as a whole shall propose and adopt standards for planetary science data archiving, exchange and access, and will implement accompanying tools in the areas, such as, however not restricted to:  long-term data preservation  data modeling  data dictionary management  interoperability  data generation, validation, access, exchange, visualization and mining  services registry IPDA Charter

Trieste, May 19, 2008IVOA Interoperability meeting International Planetary Data Alliance Membership The IPDA is represented by a Steering Committee. Membership in the Steering Committee is comprised of representatives from any space agency, scientific research institute, university or other organization approved by the Steering Committee that indicate a willingness to participate fully in the IPDA activities and provide the commensurate level of support for defining and implementing the IPDA standards. The Steering Committee is led by a chairperson and a deputy chairperson nominated by the Steering Committee for a maximum two years term. The IPDA activities is supported by Projects. The IPDA Projects are formed, and a Project Leader is nominated, by the Steering Committee. The Steering Committee define requirements for IPDA Projects and oversees their development We are going to be under the auspices of COSPAR: at the 2008 COSPAR Meeting in Montreal a resolution will be presented.

Trieste, May 19, 2008IVOA Interoperability meeting International Planetary Data Alliance Objectives The data standards within the IPDA, including the data models and derived dictionaries, are based on the NASA Planetary Data System (PDS) that is the de-facto standard for all planetary data at the time of the IPDA founding. The work on the data standards will not be restricted to planetary data sets only. Their use for solar system data sets in general will be encouraged, whenever possible. IPDA will also examine possibilities of integrating data and applications from other data sources, i.e., ground-based observations, in-situ probes, numerical models, forecasts, etc.

Trieste, May 19, 2008IVOA Interoperability meeting PDS Data Model Data Set Organization The PDS Standards Reference provides a specification for the organization of a data set using a storage medium directory structure.

Trieste, May 19, 2008IVOA Interoperability meeting PDS Data Model What is a PDS Data Product? PDS_VERSION_ID = PDS3 DD_VERSION_ID = LABEL_REVISION_NOTE = /* FILE CHARACTERISTICS */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 324 FILE_RECORDS = 334 LABEL_RECORDS = 7 /* POINTERS TO DATA OBJECTS */ ^IMAGE = 8 ^HISTOGRAM = 333 /* IDENTIFICATION DATA ELEMENTS */. /* DATA OBJECT DEFINITIONS */ OBJECT = IMAGE. END_OBJECT = IMAGE OBJECT = HISTOGRAM..END_OBJECT = HISTOGRAM END Data Product LabelData Object +

Trieste, May 19, 2008IVOA Interoperability meeting PDS Data Model What is a Data Object? Primary Objects –IMAGE –QUBE –SERIES –SPECTRUM –SPREADSHEET –TABLE Secondary Objects –HEADER –HISTOGRAM –PALETTE

Trieste, May 19, 2008IVOA Interoperability meeting PDS Data Model What is a PDS Label? PDS data product labels are required for describing the contents and format of each individual data product within a data set. –PDS data product labels are written in the Object Description Language (ODL). The PDS has established standards for the naming and definition of Data Elements and Data Objects used in product labels. –These are documented in Planetary Science Data Dictionary (PSDD).

Trieste, May 19, 2008IVOA Interoperability meeting IPDA System Architecture The IPDA Reference System Architecture is decomposed into three core pieces: –Process Architecture Describes a set of standard processes for planetary science archive data systems –Data Architecture Describes a set of data standards for planetary science archive data systems –Technology Architecture Describes a set of standards for enabling interoperability between planetary science archive data systems IPDA has initiated projects in each of these areas A Reference Architecture is a set of best practice specifications that can be used for guiding the implementation of a system

Trieste, May 19, 2008IVOA Interoperability meeting International Data Standards Identify the existing subset of standards used by PDS/PSA which are appropriate for internationalization Develop a mechanism for management of the standards at an international level (e.g., coordinated through the IPDA Archive Data Standards Project) Align existing agency standards and processes with the internationalization Data Object Model Standards Structure (IPDA and Agency Level)

Trieste, May 19, 2008IVOA Interoperability meeting Interoperability among planetary science archives Planetary Data Access Protocol (PDAP) –Standard protocol under assessment Interoperability Pilot Projects –PDS/ESA Completed; shared Mars Express and Mars Odyssey data between PDS and PSA –Venus Express –Hayabusa PDS/PSA Interoperability Pilot Project

Trieste, May 19, 2008IVOA Interoperability meeting A devoted session at COSPAR 2008 (July 13-20, 2008): “Presentation of the International Planetary Data Alliance – An integrated approach to data access” Next Steering Committee Meeting: July 2008 before the COSPAR 2008 (Montreal) IPDA Next Future

Trieste, May 19, 2008IVOA Interoperability meeting BACKUP SLIDES

Trieste, May 19, 2008IVOA Interoperability meeting IPDA Members ASI (Italian Space Agency) BNSC (British Space Agency) CNES (France) DLR (Germany) CNSA (China Space Agency) Canada ESA (European Space Agency) ISRO (Indian Space Agency) JAXA/ISAS (Japan Space Agency) NASA (U.S. Space Agency) RAS/RKA (Russia)

Trieste, May 19, 2008IVOA Interoperability meeting IPDA Organization IPDA Organization Model