1. vers. 20070524 national spatial data infrastructure training program vers. 20100901 national spatial data infrastructure training program Implementing the NSDI Implementing interoperable data models, protocols, and a service oriented architecture to develop data in support of National Spatial Data Infrastructure Geospatial Interoperability - Introduction and Overview Serving Transportation Data Through the NSDI

2. national spatial data infrastructure training program Geospatial Interoperability - Introduction and Overview 1 Learning Objectives After completing this lesson the student can: explain the concept of geospatial interoperability list the benefits of geospatial interoperability explain the meaning of interoperable protocols and their importance to service oriented architecture describe an overall strategy for implementing a standards-compliant data service in support of the NSDI data themes explain why a standard information model like the FDS is essential for gaining the real benefit of shared data access resources for further understanding and implementation

3. national spatial data infrastructure training program Geospatial Interoperability - Introduction and Overview 2 Prerequisites for the Course This training material is intended to reach individuals with a range of expertise and experience in the various disciplines that are brought together in any geospatial analysis. A fundamental knowledge of the following will be very helpful: Some knowledge of object oriented data structures and the concept of object inheritance. Familiarity with the Universal Modeling Language (UML), especially class diagrams. Familiarity with the Extensible Markup Language (XML) and an awareness of how other languages are derived from it. Familiarity with the XML Schema schema definition language. Some awareness of the Geography Markup Language (GML) Readers / students should also be familiar with the data and the GIS capabilities of their respective institutions.

4. national spatial data infrastructure training program Geospatial Interoperability - Introduction and Overview 3 The National Spatial Data Infrastructure The Federal Geographic Data Committee (FGDC) defines the National Spatial Data Infrastructure - the NSDI - as "a physical, organizational, and virtual network designed to enable the development and sharing of this nation's digital geographic information resources.”

5. national spatial data infrastructure training program Geospatial Interoperability - Introduction and Overview 4 Definition: Geospatial Data Geospatial data are data referenced to a location on the earth, either directly (by coordinates) or indirectly (by geographic identifier) Most data have geospatial content everything we do happens somewhere!

6. national spatial data infrastructure training program Geospatial Interoperability - Introduction and Overview 5 In these training materials the term “open standards” means that the standards documents are: Freely and publicly available Non discriminatory Free of license fees Vendor neutral Data neutral Agreed to by a formal, member based consensus process Definition: Open

7. national spatial data infrastructure training program Geospatial Interoperability - Introduction and Overview 6 Definition: Interoperability "capability to communicate, execute programs, or transfer data among various functional units in a manner that requires the user to have little or no knowledge of the unique characteristics of those units“ Source: OGC Abstract Specification Topic 12: Services. Derived from ISO 2382-1. Alternatively: “the ability of a system or a product to work with other systems or products without special effort on the part of the user. Increasingly important as resources on the network become accessible to an ever greater variety of software and systems.”

8. national spatial data infrastructure training program Geospatial Interoperability - Introduction and Overview 7 OGC Standards OGC Standards define interoperable services and encodings that enable the Spatial Web, and have been adopted to provide an interoperable service infrastructure for supporting the NSDI Examples WMS - Web Map Service  The WMS responds to requests to deliver maps WFS - Web Feature Service  The WFS responds to requests to characterize and deliver data

9. national spatial data infrastructure training program Geospatial Interoperability - Introduction and Overview 8 Interoperability: Benefits Procurement Flexibility make optimal “buy” vs. “build” decisions  avoid over-dependence on a single vendor – or on homegrown solutions! broadened product acquisition opportunities  mix and match components minimize risks as technologies change leverage legacy investments Interoperability boosts efficiency… maximize your access to outside information resources maximize outside access to your information resources ready access to data; data integration work more quickly and cheaply

10. national spatial data infrastructure training program Geospatial Interoperability - Introduction and Overview 9 Easier access to multiple online info sources and services Easier access to multiple online info sources and services Use and reuse different vendor solutions. Use and reuse different vendor solutions. Geoparser Clearinghouse Geoparser Vendor Data Local Government National Government Other Collections Clearinghouse Whoville Cedar Lake Whoville Cedar Lake Buildings Roads Images Targets Boundaries... Catalog View Common interfaces enable interoperability Queries extract info from diverse sources Integrated View Gazetteer Coordinate Transform Web Mapping Server, Web Feature Server, Web Coverage Server Catalog Services Other Services Metadata Data Metadata Data Metadata Data Metadata Internet Geoparser Geocoder Benefits of Geospatial Interoperability Reduce deployment costs by reusing information from other communitiesReduce deployment costs by reusing information from other communities Meet requirements for Citizen access.Meet requirements for Citizen access. Foundation for interoperable service networksFoundation for interoperable service networks Standards reduce risk and lower costsStandards reduce risk and lower costs

11. national spatial data infrastructure training program Geospatial Interoperability - Introduction and Overview 10 Goal = common semantics across different environments Java Profile Web Services Profile Web Services Profile Other Profiles Other Profiles Profile Development Abstract Standards Cross-platform compatibility Figure © NASA

12. national spatial data infrastructure training program Geospatial Interoperability - Introduction and Overview 11 Results from a NASA GIO study, completed May 2005 : Standards reduce risk and lower costs Other Key Findings & Results: Standards-based projects have lower M&O costs than those relying exclusively on proprietary products for data exchange. Standards-based projects have greater system planning and development costs. Maintenance and Operations costs are higher for projects that do not implement open standards.  This category is exposed to the greatest risk over time due to lack of extensibility and flexibility. Note: In follow-on projects that use open standards, planning costs are likely to be significantly reduced, because open standards and specs, and corresponding practices, have already been put in place. Reference: http://www.egy.org/files/ROI_Study.pdf Return on Investment

13. vers. 20070524 national spatial data infrastructure training program vers. 20100901 national spatial data infrastructure training program Implementing the NSDI Interoperability and the NSDI

14. national spatial data infrastructure training program Geospatial Interoperability - Introduction and Overview 13 Interoperable Data Services Interoperable data distribution services based on OGC standards share the following characteristics: standardized interfaces among interoperating clients and servers  the consistent interfaces are key to interoperability! data remain in place data can be stored in distributed locations, on many servers throughout the internet existing in-house tools and applications remain viable standards-compliant client software can communicate with any service instance

15. national spatial data infrastructure training program Geospatial Interoperability - Introduction and Overview 14 Service Oriented Architecture Data networks based on OGC services conform to the notion of a service oriented architecture (SOA) SOAs ensure consistency of interfaces among services consistent interfaces enable the creation of client software that can communicate with any of the services The NSDI network includes services that are compliant with OGC standards One OGC service in particular that enables delivery of FDS-compliant transportation data is the Web Feature Service (WFS) more info about the WFS is presented later in this module and in others

16. national spatial data infrastructure training program Geospatial Interoperability - Introduction and Overview 15 Interoperable Protocols and SOAs SOAs are constructed using interoperable protocols Interoperable protocols are: a set of messages that compliant programs are able to send, receive, and interpret defined by that standard set of messages A interoperable web service is a web application that uses an interoperable protocol A group of interoperable web services deployed together collectively form an SOA

17. national spatial data infrastructure training program Geospatial Interoperability - Introduction and Overview 16 Any compliant client can access any compliant service It would seem that the interoperability problem is solved, at least in theory Interoperable Connectivity Any compliant web service Any compliant client web application

18. national spatial data infrastructure training program Geospatial Interoperability - Introduction and Overview 17 Full Interoperability Still Not Available For many practical cases, the interoperability problem has been solved: a service-oriented web architecture has been defined and increasingly broadly deployed However, service level interoperability does not guarantee that the data provided by different servers are at all similar This is true even if the data in the different servers describe exactly the same kinds of information about the same real-world entities!

19. national spatial data infrastructure training program Geospatial Interoperability - Introduction and Overview 18 Different data sets often use different concepts, reflect different models, and store different details for the same kinds of real-world entities I.e., their semantics are inconsistent Software intended to analyze diverse data or render them properly for visualization have no consistent means of interpreting them and thus knowing what to do Semantic Mismatch WFS Client road 2 road 1

20. national spatial data infrastructure training program Geospatial Interoperability - Introduction and Overview 19 Issues in Semantic Mismatch Terminology The same term can mean different things. Different terms can mean the same - or nearly the same - thing. Some terms may not be known at all by many systems. Information model - objects of interest may be defined differently; they may have different components and different relationships. Implications - a running piece of software needs to know what to do when it encounters incompatible differences in the concept of what an object is. Yet another Information Community’s Schema Traffic corridor is: _No. of vehicles/hour _Limited access _Lanes …. Another Information Community’s Schema Highway is: _Pavement thickness _Right of way _Width …. One Information Community’s Schema Road is: _Width _Lanes _Pavement type ….

21. national spatial data infrastructure training program Geospatial Interoperability - Introduction and Overview 20 A standard set of structures and definitions - a standard information model - is therefore essential to gain the real benefit of data sharing The solution: translate from spatial data that conform to a local schema that reflects the local data model, and data that conform to a standard schema that reflect the standard model, and share all information using the standard model The FGDC Framework Data Content Standard - the FDS - is just such a standard model Information Interoperability A Standard Model is Essential

22. national spatial data infrastructure training program Geospatial Interoperability - Introduction and Overview 21 Yet another Information Community’s Schema Traffic corridor is: _No. of vehicles/hour _Limited access _Lanes …. Another Information Community’s Schema Highway is: _Pavement thickness _Right of way _Width …. One Information Community’s Schema Road is: _Width _Lanes _Pavement type …. Transform Information Structures Provide Semantic Translation New Information Community Schema: the FDS Road is: __ Segments __ Paths __ Attributes Transforming to a Standard Schema

23. national spatial data infrastructure training program Geospatial Interoperability - Introduction and Overview 22 Process for transforming to a standard schema: Find feature definitions in the two data models that match, or almost match. Then configure software to translate data based on these equivalencies. The configuration process may reveal that some feature definitions are too dissimilar to translate directly. Information Interoperability Transforming to a Standard Schema

24. national spatial data infrastructure training program Geospatial Interoperability - Introduction and Overview 23 Application Schema (global, or standard – e.g., the FDS) Application Schema (local) Is this the same as that? Almost! The Matching Process Is Manual

25. national spatial data infrastructure training program Geospatial Interoperability - Introduction and Overview 24 Application Schema (global, or standard – e.g.,FGDC) Application Schema (local) maps elements in one schema to elements in another schema… A server configured with, or connected to the transformation software can respond to a query for a feature of one type by delivering a feature of another, equivalent or nearly identical type. What the Transforming Software Does

26. national spatial data infrastructure training program Geospatial Interoperability - Introduction and Overview 25 After configuration, two data sets using the two different data models can be translated "on-the-fly." Core Schema (FGDC) Application Schema (local) maps elements in one schema to elements in another schema Translator … may translate as… Automated Conversion

27. national spatial data infrastructure training program Geospatial Interoperability - Introduction and Overview 26 Query: GetFeature (Standard Schema) Result: a feature (Standard Schema) User's web browser FDS Schema Local Schema Translator Data Repository Configuration for On-The-Fly Translation (Standard Schema exchanged internally) Server System WFS Interface Local or Network Data Request (Local Schema) Data Returned (Local Schema)

28. national spatial data infrastructure training program Geospatial Interoperability - Introduction and Overview 27 The FDS and Semantic Harmonization The Framework Content Data Standard (FDS) … provides a semantically well-defined set of concepts provides standard encodings  one encoding uses the full GML implementation  one encoding uses the GML Simple Features profile, level 0  both encodings conform to the same semantics, the same abstract models, and the same UML expressions of those models encompasses a fundamental set of concepts already used throughout the transportation industry specifies data objects that can be served directly through a WFS

29. national spatial data infrastructure training program Geospatial Interoperability - Introduction and Overview 28 Serving FDS Data Through the NSDI The process of publishing your data on the web so that it becomes part of the NSDI is essentially: map out the semantic relationships between the elements of your data and the objects in the FDS decide on a strategy for managing the conversion process  e.g., on-the-fly conversion vs. preprocessing and storing identify / deploy software that can convert your data from its native format into the FDS standard GML encoding  interpreted text-processing (scripting) languages are often used for this  GIS systems often include their own scripting capabilities select / deploy Web Feature Service software capable of implementing your strategy, provision with your data, and run!  products differ in the features they offer These topics are covered in detail in Modules 4 and 5 of this course Modules 2 and 3 provide essential background and context

30. national spatial data infrastructure training program Geospatial Interoperability - Introduction and Overview 29 Software Listings The OGC Products Pages are the most accurate and comprehensive source of information about software products that can support the FDS see http://www.opengeospatial.org/resource/productshttp://www.opengeospatial.org/resource/products Look for products that support WFS and a version of GML required for the FDS: GML 3 or GML 3 Simple Features Profile (GML 3L0) There are also resources, including free client and utility software, at http://frameworkwfs.usgs.gov/

31. national spatial data infrastructure training program Geospatial Interoperability - Introduction and Overview 30 Points to Consider During This Training 1. Publishing your data through the NSDI is not difficult. 2. The process can be time consuming, but it can be factored into many much smaller tasks. 3. The process requires no special hardware, no particular vendor's software, and no fundamental change in custodial policy or practice. 4. Consumers of your data (including in-house) who need to integrate with other sources of information can benefit substantially immediately upon deployment. 5. Compatible technology is readily available for deploying services as well as for client-side (e.g., visualization or analytic) software applications.

32. national spatial data infrastructure training program Geospatial Interoperability - Introduction and Overview 31 The General Feature Model and Geography Markup Language Next Lesson