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Esri's Continued Commitment to Standards and Interoperability
Continued...

Promoting Standards and Interoperability

The open GIS movement began shortly after the advent of all-relational models capable of storing both spatial and attribute data in a relational database. Standards organizations, such as OGC, the International Organization for Standardization (ISO), and FGDC, began promoting the idea of data sharing through spatial data standards. The early work of these organizations focused on sharing simple spatial features in a relational database. This enabled interoperability between the commercial GIS vendors. OGC, an international industry consortium of private companies, government agencies, and universities, published an open spatial standard called the Simple Features Specification.

Esri was the first vendor with products that successfully completed OGC conformance testing and the only vendor with both client and server products that conform to the OpenGIS Simple Features Specification for SQL. ArcSDE uses the default binary schema for Oracle and SQL Server, which is fully compliant with the OpenGIS Simple Features Specification for SQL's binary geometry. ArcSDE also provides support for additional GIS data types, such as z values, measures, and annotation, and support for raster and survey data that extends beyond the OGC specification.

The emergence of Web services provides a framework for publishing, discovering, and using GIS applications and data.

Esri has developed OGC-supported extensions to ArcGIS and ArcIMS. The ArcExplorer—Java Edition Interoperability extension reads and writes GML schemas and documents. The OGC Web Map Service (WMS) connector enables ArcIMS to provide Web map services that adhere to the OpenGIS Web Map Service Implementation Specification. The OGC WMS connector produces maps of georeferenced data in image formats (PNG, GIF, JPG) and creates a standard means for users to request maps on the Web and for servers to describe data holdings.

The OGC Web Feature Service (WFS) connector enables ArcIMS to provide Web feature services that adhere to the OpenGIS Web Feature Service Implementation Specification. The connector provides users with access to geographic (vector) data, supports query results, and implements interfaces for data manipulation operations on GML features served from data stores that are accessible via the Internet. The WMS and WFS connectors are described in greater detail in an accompanying article, "The Next Wave of Interoperability Via Web Services." Visit the Esri Interoperability Technology Download Center at www.esri.com/standards to download the OGC connectors for ArcIMS and the ArcExplorer—Java Edition Interoperability extension.

By developing products based on open standards, Esri has ensured a high level of interoperability across platforms, databases, development languages, and applications. From creating standards to reviewing standards to integrating them into products, Esri is involved in every phase of open standards development and works directly with 12 major international and United States GIS and information technology standards and interoperability organizations as well as other related organizations. Another article in this section, "Working With GIS and IT Organizations," provides resources for learning more about these organizations.

Esri's support for standards and interoperability, both in GIS data and technology interoperability and the interoperability of GIS technology with other information technologies, has benefited users in organizations both large and small.

By taking advantage of all the interoperability strategies that have been developed, CenterPoint Energy, the third largest publicly traded natural gas delivery company in the United States, is building an enterprise GIS solution. CenterPoint Energy uses GIS throughout all of the operational parts of its organization. The County of Lexington, South Carolina, an early adopter and innovative user of GIS, employed ArcSDE and ArcIMS to break down information silos and share 14 years' accumulation of GIS data through map services that benefit not only departments throughout the county but also county residents.

Advances in GIS software based on standards and interoperability have made national and international GIS initiatives, such as the National Spatial Data Infrastructure (NSDI), possible. Data standards and a high level of interoperability are requisite for these ambitious projects. NSDI is a national strategy for promoting geospatial data sharing in the government and private sectors and reducing duplication of effort.

Long-Range Strategies

As GIS technology continues to evolve, many organizations want to know what will be the best long-range solution for data sharing and interoperability. Esri believes a complete GIS infrastructure, including a loosely coupled system architecture using Web service interfaces and common information models and formats, represents the best strategy for supporting a network of heterogeneous systems. Esri has committed much of its research and development efforts to this approach.

The Geography Network is an example of a GIS implementation within a Web services framework. Esri refers to this framework as the g.net architecture and provides products that enable users to create a full implementation of g.net architecture. ArcIMS provides both GIS services as well as broker services (metadata services). Esri-developed clients, such as ArcGIS Desktop, ArcExplorer, MapObjects—Java Edition, and ArcPad, can integrate one or more of these Web services within existing applications.

With Web services, GIS applications aren't tied to the spatial schema of a specific DBMS vendor. GIS vendors can manage data using the methods and formats best suited to specific software tools and database environments. Server-to-server sharing of data and services, instead of doing this at the client level, allows GIS vendors to build and manage data and provide GIS services (e.g., data, maps, and geoprocessing) to a larger audience in a common environment. See the accompanying article "Web Services: A Standards-Based Framework for Integration."

For companies such as Five-Ten, this Web service strategy is already paying off. Five-Ten makes and markets technical footwear for climbing, trail running, paddling, and other sports with demanding shoe requirements. Its Web site identifies the nearest dealer, routes customers to the store, and generates map and turn-by-turn directions using an assortment of ArcWeb Services. Their use didn't require the company to develop any GIS expertise or data.

GIS as Information Infrastructure

Esri continues to build generic GIS technology that empowers users and works in today's heterogeneous distributed environment. ArcGIS 9, the next major release, is a platform for building geographic information systems that provides a single, unified software architecture for GIS applications, services, and development. ArcGIS 9 is built on and extended using ArcObjects. It encompasses three major components—ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

ArcGIS Engine is a simple API-neutral, cross-platform development environment for ArcObjects. Its object library will make full GIS functionality available through both fine- and course-grained components that can be used in Java, .NET, C++, and COM development environments.

ArcGIS Desktop extends the engine with desktop application frameworks and user interface components.

The ArcGIS Server will provide comprehensive GIS functionality that includes mapping, data management, and geoprocessing and extends the ArcGIS Engine with Web application templates, controls, and services. It uses open Web services interfaces (e.g., Java API, .NET API, and a generic Web service API that uses XML/SOAP). With ArcGIS 9, XML will provide a representation of the full geodatabase, making it independent of any DBMS container. All aspects of the geodatabase data model or a subset of the geodatabase can be exported, and exported files can be imported into an existing database. The XML export format is organized into a data definition section that defines all the geodatabase elements and a data section that is based on the OGC Simple Features Model.

A Continuing Commitment

Esri continues to make major investments in the development and implementation of open GIS standards and interoperability to serve users and promote the sharing of geographic data across all GIS platforms. Interoperability and standards are required to deliver a distributed, multipurpose GIS. Esri is developing information modeling, system architecture, and software engineering that incorporate standards and ensure interoperability, not just in the GIS world, but also in the larger IT community. The goal is to create one infrastructure that works everywhere—across all platforms and technologies and on all types of devices. For more about the latest developments in standards and interoperability as related to GIS and links to IT and GIS standards organizations, visit www.esri.com/standards.