international planetary data alliance (ipda) · 2017. 11. 24. · the main objective of ipda is the...

Paris, 13/12/2007 Atelier VO-Planeto

International Planetary DataAlliance (IPDA)

A Standards Initiative for Building Compatible Archives

Maria Teresa CapriaINAF – IASF Rome, Italy


Background• Scientific community in the U.S. decided in the eighties to setup a data

system for planetary related data (ground-based, laboratory data, spacedata), the Planetary Data System (PDS)

• Scientific community in Europe got acquainted to the PDS-Standard, asmost data originated from NASA missions; ESA adopted the PDS-Standard as the base standard for it’s archival system, the PlanetaryScience Archive (PSA)

• NASA/PDS and ESA/PSA have worked closely together to coordinatearchiving 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


Background

• In 2005, the PSA and PDS initiated an effort to develop common interoperabilitystandards for accessing and distributing data internationally from national planetaryscience archives; this includes

–A protocol for finding, accessing and retrieving science products from across agency systems–Common semantics for discipline-specific queriesThe plan is that joint missions in the future will use the interoperabilityprotocol rather than submitting and archiving data from another agency in a localsystem.

Other space agencies need to setup similar archival systems, includingstandards, tools, services, etc in the coming years to serve ‘their’ scientificcommunity

–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


International Planetary Data Alliance

Mission Statement

The International Planetary Data Alliance (IPDA) is aclose association of partners with the aim of maintainingand continuously improving the quality and services toplanetary science data from ground or space basedinstruments.The specific mission of the IPDA will be to facilitateglobal access and exchange of high quality scientific dataproducts managed across international boundaries andorganized by a set of governing data standards.

In 2006, the International Planetary Data Alliance was established whichincludes participation from major space agencies around the world.


International Planetary Data Alliance Basic Idea on IPDA Setup

• COSPAR– Proposed to be under the auspices of COSPAR: pursuing a

COSPAR resolution at the 2008 Meeting in Montreal– Biannual Meeting at COSPAR conference

• Steering Committee– defined by Charter– with representatives from all space agencies/interested institutions– yearly meeting– define requirements for IPDA Projects and oversees their developmnent– nominate IPDA Project Leaders

• Communication Channels– IPDA will be based on electronic information exchange

• WWW presence– url selected: http://planetarydata.org


IPDA Organization

IPDA Steering Committee

COSPAR

IPDA Project

Project Leader

Project Members

IPDA Project

Project Leader

Project Members

Chairperson

IPDA Project

Project Leader

Project Members

IPDA Project

Project Leader

Project Members

IPDA Project

Project Leader

Project Members

IPDA Project

Project Leader

Project Members

IPDA Project

Project Leader

Project Members

IPDA Project

Project Leader

Project Members

IPDA

Member Agency

Agency Representative


Member Agency



Member Agency



Member Agency



Member Agency



Member Agency



IPDA OrganizationModel


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 implementingthe 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 will be supported by Projects.• The IPDA Projects are formed, and a Project Leader is nominated, by the

Steering Committee.


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)


International Planetary Data Alliance Objectives

The main ob jective of IPDA is t he enhancement of t he resea rcha ctivities in the worldwide planetary community.The IPDA as a whole shall propose and adopt standards forplanetar y sc ienc e d ata ar chiv ing , ex chang e and acc ess, and willimplement accompanying tools in the areas, such as, however notrestricted to:

long-term data preservationdata modelingdata dictionary managementinteroperabilitydata generation, validation, access, exchange, visualization and miningservices registry

IPDA Charter


International Planetary Data Alliance Objectives

The data standards within the IPDA, including the data models and deriveddictionaries, 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 setsonly. 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.


IPDA Reference SystemArchitecture

• The IPDA Reference SystemArchitecture is decomposed intothree core pieces:– Process Architecture

• Describes a set ofstandard processes forplanetary sciencearchive data systems

– Data Architecture• Describes a set of data

standards for planetaryscience archive datasystems

– Technology Architecture• Describes a set of

standards for enablinginteroperability betweenplanetary sciencearchive data systems

• Each of the above will provide aset of deliverables to guidesystem development andoperations A Reference Architecture is a set of best practice specifications that

can be used for guiding the implementation of a system


Next Steering Committee Meeting: July 2008One week before the COSPAR 2008 (Montreal)

Pursuing a COSPAR resolution at the 2008 Meeting in Montreal

A devoted session at COSPAR 2008 (July 13-20, 2008): “Presentation of the International Planetary Data Alliance – An integrated approach to data access”

IPDA Future


BACKUP SLIDES


Projects: 2007-2008Project Name Leader

<Program> *COSPAR (continuation) Reta Beebe *Banner/LOGO Thomas Roatsch

<Standard Definitions> *IPDA Requirements Dan Crichton *Standard Data Model, Assessment of Draft Peter Allan *Data Dictionary Modeling Steve Hughes

<Interoperability> *Venus Express Interoperability Nancy Channover *Small-Body Interoperability Demonstrator Iku Shinohara *PDAP, Assessment of Draft Protocol Someone from JAXA *Interoperability: Query Model Iku Shinohara


PDS Data Model• Brief overview of a PDS Data Set• What is a data product?• What is a data object?• What is a PDS label?


PDS Data Set Organization• The PDS StandardsReference provides aspecification for theorganization of a dataset using a storagemedium directorystructure.

• A single volume (unitof physical medium) ispreferred.


What is a PDS Data Product?

PDS_VERSION_ID = PDS3DD_VERSION_ID =LABEL_REVISION_NOTE =

/* FILE CHARACTERISTICS */RECORD_TYPE = FIXED_LENGTHRECORD_BYTES = 324FILE_RECORDS = 334LABEL_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 = HISTOGRAMEND

Data Product LabelData Object+


What is a Data Object?• Primary Objects

– IMAGE– QUBE– SERIES– SPECTRUM– SPREADSHEET– TABLE

• Secondary Objects– HEADER– HISTOGRAM– PALETTE


What is a PDS Label?• PDS data product

labels are required fordescribing thecontents and formatof each individualdata product within adata set.– PDS data product

labels are written inthe ObjectDescriptionLanguage (ODL).

• The PDS hasestablished standardsfor the naming anddefinition of DataElements and DataObjects used in productlabels.– These are

documented inPlanetary ScienceData Dictionary(PSDD).

Attached

Detached


IntroductionDefinition of a Data Model

•Data Model - A data model isan abstract model that describeshow data is represented andused.

•A planetary scientist working onthe PDS describes a data modelas “the organization of themetadata and structure of thedata

Image Description (ODL)

Image Class (Object-Oriented)

An Image


Information ModelOverview of Process

• Process for Generating the DraftInformation Model

– The Information Model is captured inan ontology modeling tool

• PDS Data Model is used as abaseline

• Representative data products inthe PDS archive are used toconstrain the model and identify“core” data formats.

– Resulting database is exported toASCII files

– Exported files are used to generatefinal document.


Final DeliverableInformation Model

Information Model - AnInformation Model is a type ofData Model.

– A data model is generallyassociated with simpleritems such as data formatsand data structures.

– An information model canbe thought of as a datamodel that has a richer setof relationships.

– These relationships add"meaning" and "changedata into information".

– For example, associating aimage description with animage map projectioncould be considered to beadding meaning.

Image Description(ODL)

Image MapProjection

Registered to

DataModel

InformationModel


Project Approach

• Identify the existing subset of standards used by PDS/PSA which are appropriate for internationalization


Project Scope• The scope of this project is the IPDA Archive Data Standards focusing specifically on

the IPDA Data Model. The primary deliverables are a requirements document and adraft IPDA Common Data Model.

• The Data Model includes the following components.– Data Dictionary of Terms– Object Models

• Data Formats• Upper Level• Product• Label• Others

Note: The “grammar”, expression of the data model in a particular language (i.e.ODL) will be addressed by another project.


Information ModelUpper Level Model

• Upper Level Model– PDS catalog objects are captured from

their definitions in the Planetary ScienceData Dictionary (PSDD)

• Mission, Instrument, Data Set, etc– Additional modeling information is

captured from the operational PDSCatalog database schema and earlyPDS design documents


Information ModelPDS Data Products and Labels

• PDS Data Products andLabels– PDS data products

and their labels arecaptured from theirdefinition in the PDSStandards Reference

– Groups of dataelements areidentified andmodeled

• Identification DataElements

• Descriptive DataElements

– Base data productswere derived from thesubmitted dataproducts from thenodes.


Information ModelData Formats

• Data Formats– Generic Data Formats

• Extracted and ingesteddefinitions of generic PDSobjects from PlanetaryScience Data Dictionary(PSDD)

– Base Data Formats• Derived from the generic data

formats using only therequired data elements

– Source Data Formats• Collected examples of well-

formed, common dataproducts from PDS disciplinenodes and the PSA.

• Defined data formats for eachPDS object in the dataproduct label (e.g. VikingMDIM Image, RSS BinaryTable)

– Core Data Formats• Derived from base data

format and similar sourcedata formats. (i.e. a genericdata format with “used”optional data elements)


Information ModelData Dictionary

• Data Dictionary of Terms– PDS data element definitions were

extracted from the PlanetaryScience Data Dictionary (PSDD)and ingested into the modeling tool.

– Elements used in the object classdefinitions are considered part ofthe core and included in theinformation model.


Backup


GlossaryData Model - A data model is an abstract representation of the "data"

used by an organization, such that a meaningful interpretation of thedata may be derived from those properties thought to be relevant tothe users of the data. The data model defines specific groups ofentities, and their attributes, and their inter-relationships.

Class Diagram - A class diagram is a type of static structure diagramthat describes the structure of a system by showing the system'sclasses, their attributes, and the relationships between the classes.

Information Model – An Information Model is a type of data model thathas an emphasis on a rich set of relationships. These relationshipsadd "meaning" and "change data into information". An Informationmodel’s scope typically encompasses a large and complex domain.

Object Model – An object model is an abstract model that describes howdata is represented and which uses object-oriented concepts (e.g.object classes).


Agency Example:PDS Alignment toInternational Standards

international planetary data alliance (ipda) · 2017. 11. 24. · the main objective of ipda is the...

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