Slide 1 SDTSSDTS FGDC CWG SDTS Revision Project ANSI INCITS L1 Project to Update SDTS FGDC CWG September 2, 2003

Slide 2 SDTSSDTS FGDC CWG SDTS Revision Spatial Data Transfer Standard Background/History Philosophy Model Levels Content Implementation

Slide 3 SDTSSDTS FGDC CWG SDTS Revision Requirements for Change –Technology Evolution –Standards Evolution Role of SDTS Revision scope Candidate updates Plans

Slide 4 SDTSSDTS FGDC CWG Background/History NCDCDS & FICCDC – 1980s NIST FIPSPUB – 1994 ANSI NCITS INCITS L1 –InterNational Committee for Information Technology Standards –L1 Geographic Information Systems

Slide 5 SDTSSDTS FGDC CWG SDTS Philosophy Self-documenting Complete - containing everything needed to enable informed use Includes metadata (reference system, data dictionary, data quality information, etc.) Information for software and users to read Abstract model based Implementation Modular

Slide 6 SDTSSDTS FGDC CWG Model Levels Conceptual [defns] –The philosophy, ideas, concepts and definitions that form the basis and set the perspective Logical [modules] –give substantive shape to the ideas from the conceptual layer Format [files] –Using the structures to build the end product: “a set of files for data transfer”

Slide 7 SDTSSDTS FGDC CWG Content What is the content of a transfer? Features & Spatial Objects –Vector: point, node, chain, polygon, string, arc, link –Raster: grid, pixel Attributes –user-defined –standard list

Slide 8 SDTSSDTS FGDC CWG Content (2) Metadata –Data dictionary, spatial referencing, data quality, symbology tables, security, global information Graphics Ancillary information

SDTS Module Categories Identification Catalog /Directory /Cross Ref /Spatial Domain Security Coding Spatial Reference Internal External Registration Spatial Domain Data Dictionary /Definition /Domain /Schema Transfer Statistics Lineage Positional Accuracy Attribute Accuracy Logical Consistency Completeness Vector: Point-Node Line Arc Ring Polygon Raster: Raster Definition Layer Definition Dimension Definition Cell Composite Text Representation Line Representation Symbol Representation Area Fill Representation Color Index Font Index Attribute Primary Attribute Secondary DATA QUALITY SPATIAL OBJECT GRAPHIC REPRESENTATION ATTRIBUTE GLOBAL

Slide 10 SDTSSDTS FGDC CWG SDTS Profiles

Slide 11 SDTSSDTS FGDC CWG Requirements for Change Technology Evolution –DCEs, etc. Standards Evolution –ISO TC 211 standards –OpenGIS Consortiuum specifications –W3C, Etc.

Slide 12 SDTSSDTS FGDC CWG Current SDTS Paradigm: Static Data Transfer Manifest catalogs schema coord system... Dataset spatial objects attributes composites... Encode from source Decode to target app Data Transfer

Slide 13 SDTSSDTS FGDC CWG Dynamic Interoperability Database Server catalogs schema coord system geodata Database Client schema coord system representation geodata Distributed computing environment Requests, Features, & Collections

Slide 14 SDTSSDTS FGDC CWG SDTS Role SDTS is especially suited for –Blind exchange –Archive the information content requirements necessitate –self-contained and –self-describing datasets.

Slide 15 SDTSSDTS FGDC CWG Setting Revision Scope 1.Action item to INCITS L1 membership: Review SDTS to identify recent work that has been done that would affect the rewrite of the document, i.e., better/newer concepts, and technologies identified in more recent standards. 2.Select target constructs to which to map current SDTS constructs. 3.Select target enhancements (e.g. enhanced semantic modeling).

Slide 16 SDTSSDTS FGDC CWG Candidate Mappings SDTS Constructs map to targets –Abstract (Conceptual) Model »bring into alignment w/ ISO TC suite of standards –Implementation »bring into alignment with ISO TC 211 & OGC specifications Logical Encoding

Slide 17 SDTSSDTS FGDC CWG Abstract Model Mappings Conceptual Model  ISO 191xx –Feature model »Entity vs Representation  … »Entity Attribute model  (and beyond?) –Spatial Object model »Vector  »Raster  –Graphic representation  19117

Slide 18 SDTSSDTS FGDC CWG Logical Components SDTS Logical constructs  ISO 191xx –Global components »Metadata  »Data Dictionary  (+?) »Spatial Referencing  19111

Slide 19 SDTSSDTS FGDC CWG Implementation - Encodings Current SDTS encoding: –ISO 8211, Data Descriptive File Replace ISO 8211 encoding with –XML, specifically GML (Geography Markup Language, OGC and ISO specification), and –ISO metadata encodings. Replace Graphic Symbology with OGC Style Layer Descriptors?

Slide 20 SDTSSDTS FGDC CWG Revision Project, Next Steps 1. Scope the project 2. Develop work plan 3. Enlist resources

Slide 21 SDTSSDTS FGDC CWG SDTS Revision Contact Robin Fegeas