Geospatial standards

1. Geospatial standards Geog 458: Map Sources and Errors March 1, 2006

2. Outlines • Roles of geospatial standards • Categories of geospatial standards • Developers of geospatial standards • Areas of geospatial standards

3. Why bother with standards? • Consensus is good, it avoids confusions, and it allows systematic managements of geospatial data • Documenting data characteristics with no agreement on which should be included would have too much room for interpretation → FGDC’s metadata content standards • Converting file formats between different computer systems will end up losing details if proprietary formats are not compatible with other formats → SDTS • Integrating data with different classification schemes will cause trouble in processing values properly → standardized code set (e.g. occupation code, land use type code, road class, FIPS code for locality name)

4. Value of standards • Wisely-designed standards provide the foundation to help make information systems and databases easier to use and maintain • Standards solve particular problems also, such as how to represent data efficiently or manage a communications system • In the sense standards reflect best practices in particular areas • Saves money and time (also stress?)

5. Values of geospatial standards can be reflected in three themes: • Portability • Ability to use and move data and custom applications among multiple computers and operating systems environments without re-tooling or reformatting • Inter-operability • Ability to connect and retrieve information from multiple systems • Maintainability • Ability to promote long-term and efficient updating, upgrading, and the effective use of computer systems and databases

6. Roles of standards • Portability • Data transfer • Software • Interoperability • Data access • Software functions • Maintainability • Data update • Software revisions • Hardware upgrades DB

7. What is a good standard? • So you would say that having standards is good • Sometimes, better question is not whether standards should be adopted, but rather to choose suitable standards. • In essence, standards cannot be quite flexible in the sense that we have to conform to them and things keep changing • Think about CSDGM; you spend some time in learning about it, but how would you feel if it is not considered standard anymore? • It is hard to satisfy different needs with one good super-hero kinds of standards

8. Quality of a good standard • Should reflect what’s best now, also should be flexible enough to be accommodated into future development • How do you know what’s best? • Agreement given knowledgeability in particular areas? • What do you think of CSDGM with these regards? Is it really flexible? Isn’t there any assumption on data structure and so on? Standards shouldn’t be something that defers progress

9. Categories of standards • Geospatial standards may be broadly categorized as ‘independent’ standards or ‘de facto’ standards • Independent (consensus, or formal) standards: formally approved by a recognized body through a well-defined consensus settings • e.g. FGDC CSDGM, USGS SDTS, ANSI ASCII • De facto standards: those that become accepted because of their broad popularity and use, but are not necessarily accompanied by any formal approval by an independent standards organization • e.g. Microsoft ODBC, ESRI Shapefile? thanks to either their sufficient market share or their seemingly good performance

10. Developers of standards • National government organizations • National government agencies in all industrialized nations with specific responsibility for approval of information system standards (e.g. NIST, FGDC in the U.S.) • Independent standards bodies • Formal standards bodies work in a consensus building process to adopt and promote formal standards; include representation from government agencies, professional organizations, and private companies; open policies for membership (e.g. ANSI, IEEE, CEN, ISO) • Industry consortia and trade associations • Formal or informal associations with missions for joint definition, development, and promotion of standard-based products for their customer base; created to address specific market niches (e.g. OMG, OGC) • Professional organizations • Group of professionals with missions for education, interaction between members, and review of proposed standards (e.g. URISA, IAAO, ACM)

11. Developers of geospatial standards National government organization Independent standard bodies Industry consortia

12. Areas of geospatial standards • Standards of importance to geospatial information users may be broadly categorized into low-level and high-level categories • Low-level standards • Covers technical concerns in hardware, network (e.g. Ethernet, TCP/IP), and operating system (UNIX, NT) • Important issue for interoperability • Domain of computer industry • High-level standards • Deals with database design, data exchange and presentation topics • User interface, data format/exchange, programming and application development, and user design • Developers of GIS have influence over these standards

13. Software standards • Operating systems: running applications without modification on multiple platforms • UNIX by Open Group • Windows NT, XP by Microsoft • Object management architectures: standards and compliant projects for object management and communication • CORBA by OMG • DCOM by Microsoft

14. Three strategies for geospatial data exchange and interoperability DB DB Direct Batch Translation DB DB DB Transparent Inter-operability (e.g. SQL, OGIS) Intermediate Batch Exchange (e.g. DXF, SDTS)

15. Direct batch translation • Requires specific programs to translate formats directly from one proprietary structure to another • Intermediate batch exchange • Most appropriate when data must be exchanged between several different software formats • Industry standards include DXF (AutoCAD) • Government agencies developed SDTS (neutral exchange formats that encompass comprehensive GIS database content and format information; it also includes attributes associated with map graphics, complex map feature structures, map symbology, and metadata) • Raster file format make use of some type of data compression (e.g. JPEG)

16. Transparent interoperability • Establishes interactive session between two or more databases to allow a GIS application or user query to automatically and transparently access the “external” data • Two standards facilitate this • SQL: structured query language accepted by ANSI; standard dialogue to access data, perform queries, and select records from a relational DB • ODBC: industry standard developed by Microsoft; transparent access among disparate databases • Isn’t this attribute data exchange standards? Any geospatial standards? • Spatial extensions to SQL • Open GIS Specification in progress

17. Programming and application development standards • GIS had been developed through proprietary languages (called macro language) • AML: procedural language • Avenue: transition to object-oriented language • Increasingly ‘open’ development environments (e.g. Visual Basic, Visual C++, Delphi, Java, Python) • ArcObject is a set of GIS functions to be accessed directly by industry standard programming languages • Can be written by any object-oriented languages

18. Why ‘openness’? • Maximize the efficiency of staff resources in application development • You don’t have to write the code from scratch • Application can be inherently more portable • The same code can be reused • Increase opportunities to integrate data from multiple systems and databases • Different program languages can understand data without changing the format into its proprietary one

19. What is a good standard? • A wisely crafted set of standards will promote portability, interoperability, and maintainability • Developing standards takes time and diligence to ensure that standards are adhered to as a GIS matures • A well-designed set of standards will take into account the specific needs of an organization within a broader community of users