1 PDS 4 Data Design Report PDS Management Council April 2, 2009 PDS 2010 Data Design WG

Data Architecture Scope 2

Key Deliverables PDS4 Information Model The Information Model defines the objects in the PDS archive. This includes data structures, formats, and products as well as data sets, documents, missions. PDS4 Data Dictionary Model The Data Dictionary Model provides the schema for the PDS data dictionary. The data dictionary defines the data elements used in the PDS4 Information Model. PDS Standards Reference V4.0 and V4.1 Version 4.0 of the PDS Standards Reference document will be a rewrite of Version 3.x. Version 4.1 will be an update released toward the end of the project. Grammar The Grammar will be used to capture PDS archive metadata for product labels. The plan is to replace or fix ODL. XML is being considered as an additional grammar. 3

Data Design Working Group Formed in December 2008 Personnel Steve Hughes (Lead) Mitch Gordon (Rings) Edward Guinness (Geosciences) Lyle Huber (Atmospheres) Ron Joyner (EN) Anne Raugh (SBN) Elizabeth Rye (Imaging, Standards) Steve Joy (PPI) Dick Simpson (Observer) Weekly Telecons Project Website Just released version “m” of the model to the PDS engineering website. The design documents and example labels are re-generated after the application of updates to the information model database. 4

Data Design WG Schedule 04-Dec Project and Project Members Defined 31-Dec Requirements updated 30-Apr General Data Model (Draft) 30-Apr Product Data Model (Draft) 30-Apr Data Dictionary Model (Draft) 30-Apr Grammar Options 30-Apr PDS Standards Reference (Outline) 30-Sep Data Dictionary Model (Final) 30-Sep Grammar Decision 30-Sep PDS Standards Reference (Draft) Interim - PDS and community wide review 30-Jul General Data Model (Final) 30-Jul Product Data Model (Final) 30-Jul PDS Standards Reference (Final) 5 Done Substantial Progress

PDS4 Data Product Concept Map 6 Web ViewProgrammer ViewDesigner ViewUser View

Working Group Accomplishments To Date 7 Four basic data structures Homogeneous N-dimensional array of scalars – Array_Base Heterogeneous repeating record structure of scalars – Table_Base Unencoded byte stream Encoded byte stream Identifiable Digital Product Data Product 2-D Image Product … Document Set Non-Digital Product Mission Instrument Resource Data Type Binary Data Type Decimal Integer … Character Literals Character Integer … Array_Base 2D_Array 2D_Image 2D_Spectrum 3D-Array 3D_Wavelength_Array 3D_Image 3D-Spectral_Array 3D_Time_Array Movie 3D_Spatial_Array N>3-D Array Table_Base Character_Table_Base Binary_Table_Base Draft PDS Data Dictionary Model Grammar – ODL+, XML, and AnneML Labels

Prototype ODL+ Label Template (Data Structure) 8 /* Object Section */ Object = 2D_Image axes_order = FAST2SLOW axis_length = (${axis_length}, ${axis_length}) axis_name = (${axis_name}, ${axis_name}) axis_type = (${axis_type}, ${axis_type}) axis_unit = (${axis_unit}, ${axis_unit}) byte_order = MSBF description = ${description} /* Optional */ element_bytes = ${element_bytes} /* Optional */ element_offset = ${element_offset} /* Optional */ element_scale = ${element_scale} /* Optional */ element_type = ${element_type} element_unit = ${element_unit} /* Optional */ first_element = TOPLEFT min_index = 0 number_of_axes = 2 End_Object = 2D_Image END

Prototype ODL+ Label Template (Other stuff) 9 #PDS4# /* ******* Label Template : 2D_Image_Label ******* */ PDS_Unique_Identifier = ${PDS_Unique_Identifier} /* Identification Section */ Object = Identification_Section dd_version_id = ${dd_version_id} label_revision_note = ${label_revision_note} pds_version_id = PDS4.0 End_Object = Identification_Section /* Dataset Section */ Object = Dataset_Section data_set_id = ${data_set_id} End_Object = Dataset_Section /* Instrument Section */ … /* Mission Section */ … /* Node Section */ … /* Circumstances of Observation Section */ …

Prototype XML Label – XML/Schema <xs:complexType name="2D_Image_Type <xs:element name="axis_length" <xs:element name="axis_name" <xs:element name="axis_type" <xs:element name="axis_unit" <xs:element name="byte_order" <xs:element name="element_bytes" <xs:element name="element_offset" <xs:element name="element_scale" <xs:element name="element_type" <xs:element name="element_unit" <xs:element name="first_element" <xs:element name="min_index" <xs:element name="number_of_axes" …

Prototype AnneML Label 11 PDS4 Label { Use Dictionary PDS4; Use Dictionary ; … class 3D_Image { axes_order = FAST2SLOW; axis_length = (${axis_length},${axis_length}, ${axis_length}); axis_name = (${axis_name}, ${axis_name}, ${axis_name}); axis_type = (${axis_type}, ${axis_type}, ${axis_type}); axis_unit = (${axis_unit}, ${axis_unit}, ${axis_unit}); … element_bytes = ${element_bytes}; /* Optional */ element_offset = ${element_offset}; /* Optional */ element_scale = ${element_scale}; /* Optional */ element_type = ${element_type}; element_unit = ${element_unit}; /* Optional */ … number_of_axes = 3; … };

Next Steps 12 Continue design work in preparation for Tech Session PDS Technical Staff Review Information Model Obtain consent to continue along current design path Grammar Present options and move toward adoption of one or two of the options Data Dictionary Model Present draft model and consider adoption Standards Reference Present outline and request feedback