Untangling the net - Utility GIS / Internet technology

Untangling the net - Utility GIS / Internet technology

Kathy H. Spivey
Systems Analyst

Laura Mizula
Senior Consultant

PlanGraphics, Inc. 1597 Cole Boulevard,
Suite 300, Golden, Colorado 80401

Introduction
Over the past few years, the explosion of intemet technology and intemet-enabled applications has changed the way information is distributed. Not unaffected by this information shockwave was the GIS community, who recognized a niche they can fill by deploying dynamic maps and related information on the Web. These dynamic maps are created by web-enabled GIS applications which offer users the capability of interactively obtaining graphical data.

The purpose of this paper is to introduce the reader to the concept of web-enabled GIS and the technology that supports GIS/intemet applications. Common utility-oriented GIS/intemet applications are discussed. In addition, the planning and implementation process associated with the deployment of such applications is reviewed.

GIS/Internet technology
Three GIS/intemet architectures are currently being deployed (ter Haar, 1997). Figure 1 presents common configurations for each architecture.

The first GIS/intemet architecture is raster-based. A user client, whether browsing the internet or an internal intranet, issues a mapping request (i.e., users asks for the map to be panned or zoomed, or performs a query resulting in a new map). Alternatively, the user client can also use the mouse to make a screen selection. The request or the location of the screen selection (in screen pixel coordinates) is sent by the intemet server to the map server. The map server sends the information to the map server application (which can reside either on the map server or on another workstation). The map server application converts the pixel coordinates to real-world coordinates if a screen selection was made and/or processes the query request, creates the requested map, and converts the new map into a bitmap image. The image is then converted into an HTML page and is downloaded to the intemet server which is then delivered to the user client. Each request by the user client results in the generation of a new map, and thus a new image.

The second GIS/intemet architecture that exists today is the vector-based approach. This architecture is very similar to the raster-based approach, except for the data type being passed back to the user client. Once again, the user client makes a map request through the intemet server to the map server. The map server application processes the request and generates a vector file (rather than a raster file, as in the previous approach), which can be linked back to non-graphic data stored in a database and can be tagged as active features. In order to be able to see the vector file, however, the user client must download a special plug-into enable the browser to display the information. Each map request results in the generation of a new vector file that is created and sent to the user client.

The third GIS/Intemet architecture being used is the vector-metafile approach. In this approach, the plug-in plays a critical role in the viewing of the data. Map requests made by the user client are sent through the intemet server to the map server in two steps: 1) the request triggers the creation of a metafile sets up the mapping application environment (including information about what information is to be loaded, where the information can be found, and how the information must be displayed, and 2) the plug-in requests the data associated with the map. The map server then returns to the user client only the raw data which is processed by the plug-in and displayed. Once the mapping application environment is established, each user client map request prompts the plug-in to request only the new data from the map server.

A fourth GIS/intemet architecture, developed and employed by SmallworldWeb, is the compressed-vector approach. Smallworld's web-enabled GIS technology allows access to vector, raster and intelligent data in the form of maps and reports over an enterprise's intranet. Clients on an organization's intranet use customized applications, developed using any scripting language that can package Active X controls, to perform various view and query fi.mctions. Data required for the applications is transferred from the Smallworld datastore server to the client where data is cached and manipulated via the client applications. Data served to the client is controlled through a configuration setting on the SmallworldWeb server. An optional load balancer, called the Dispatcher, handles communications between multiple clients and multiple data servers.

Figure 1 Common Configurations of GIS/Internet Architectures

A summary of some of the available GIS vendor internet/intranet offerings is shown in Table 1.

Table 1 Available GIS/Internet Packages

Package	Architecture
Autodesk MapGuide	Vector-metafile
ESRI MapObjects/IMS	Raster
ESRI ArcView/IMS	Raster
Intergraph GeoMedia Web Map	Vector
MapInfo ProServer	Raster (Vector in future)
SmallworldWeb	Compressed vector

Common utility GIS applications for the internet
The use of internet technology for collecting and providing general information is not new to the utility industry. Many utilities are now beginning to use web-enabled GIS as a way of providing access to geographic information across the utility. Although most utilities are using webenabled GIS primarily for internal use over an intranet, a few have begun to provide GIS access to customers and the general public over the internet. The most common applications in use today or being considered for fiture implementation are summarized below: Map/Drawing Access-The most common web-enabled GIS application is the simple provision of portions of a utility's GIS database to customers over the internet. Customers or employees can choose map and drawing sets to download for personal use.

Map Viewing-Although this application is more common for intranets than on the internet, this type of application has gained widespread use. Users can access a variety of map data sets and are provided with search criteria to perform queries. Most commonly, these applications provide a means for locating a specific service connection or property and then viewing key attribute data or map features in reference to the found location.

Market/Business Development-Utility marketing departments are pioneers in using web-enabled GIS. Market/business development applications are designed to attract new customers and businesses to a utility's service area. These applications allow organizations to locate infrastructure, amenities, and market statistics for an area of interest. The applications allow users to evaluate the suitability of a specific site or area for locating a business or relocating a family.

Work Management-These applications are used to manage service requests and work orders. External customers and internal employees can initiate a service request and view the status of the request or other work orders in an area.

Outage Management-These applications allow users t view planned and unplanned outages in the utility network.

Construction Design and Management-These applications facilitate the construction design and review process. Users can download portions of the GIS database as a base for construction design and can submit design drawings for review. Once construction begins, users can view the status of a particular project.

Dig Alert-This application allows users to search a site for utility infrastructure before digging. Planning and implementing web-enabled GIS
Like the traditional GIS implementation process, implementing web-enabled GIS is a complex process that requires proper planning to ensure success. Whether GIS access will be provided to internal employees over an intranet or to external customers over the internet, a well formulated plan will ensure that data access by users is fast and effective while providing the level of security required to protect the utility's data.

Needs Assessment - Plan for Success
A little planning will go a long way when it comes to implementing web-enabled GIS. Conducting a needs assessment that addresses internal, as well as external user requirements, will provide a solid foundation for formulating an implementation plan. The objective of the needs assessment process is to:
- Identify user requirements for data access;
- Identify user requirements for interactive data analysis applications;
- Evaluate and prioritize data and application requirements for implementation.
The needs assessment should be used as a tool for generating ideas about the potential applications and how those applications might benefit internal and external customers. The assessment should distinguish needs of internal users (intranet) from those of external customers (internet) as each will have a unique set of data management and security requirements. Web-enabled GIS is intended for use by internal and external customers that have relatively simple data access and analysis requirements. It is best suited for those users that can be satisfied by simply viewing data and/or executing pre-defined queries to find information specific to their individual needs. Applications that have complex processing or analysis requirements are not well suited for web-enabled applications because these types of applications require significant processing power and cannot be performed over the internet with very reliable response times. Additionally, all web-enabled GIS applications will require some level of programming effort; the more complex an application is, the higher the level of programming effort required. Thus, the focus of the needs assessment should be on users and applications that have relatively simple requirements.
1. Identifying Application Requirements
  Web-enabled GIS applications should be targeted for internal employees and external customers that have simple data viewing and querying requirements. These users do not need GIS training since all data access will be performed through the use of a standard intemet browser. For each planned web-enabled GIS application, the following should be identified:
  
  Number and Type of User-Identify all potential users of the application. Distinguish internal employees from external customers. Estimate the number of simultaneous users that will potentially access the application at one time.
  
  Data Requirements-Identify all the data sets that will need to be displayed as a part of the application. Distinguish graphic map sets from tabular reports.
  
  Processing Requirements-Identify all processing requirements associated with the application. Identi& any search criteria or data that will need to be entered by the user to initiate parts of the application. Also, identify GIS functions that will need to be invoked as a part of the application (e.g., thematic mapping, buffer creation, polygon overlay, etc.).
  
  Display Requirements-Identify how data must be displayed on screen. Identify the map scale required for graphic data and presentation format for tabular or text data.
  
  Update Requirements-Identify how frequently the data associated with the application will need to be updated to be of maximum benefit to the user.
  
  Security Requirements-Identify any security requirements for the application. Identify any controls that must be implemented to ensure sensitive data can only be viewed by the appropriate users.
2. Prioritizing Applications
  Once application requirements have been detailed, an evaluation should be performed to determine feasibility of development and to begin establishing a prioritization for development. Examine each application and evaluate the relative benefit versus cost of each application individually and then in relation to one another. Application costs considered should include technical programming costs, database development costs, hardware/software costs, and administrative costs. Application benefits might include improvements in customer service, productivity increases, and efficiency improvements. The most significant benefits for intemet applications used by external customers are improved customer service and reductions in staff time required for responding to information requests.
3. System Design
  After prioritizing applications for development and publishing, a design for the inranet or intemet should be prepared. The system design should identify the applications that will be provided; data sets that will be used; and a hardware/software/network configuration for both internet and intranet access. Hardware and software requirements will be determined by the complexity of the applications to be provided and the number of users expected to use the applications at any one time. Servers will be required for data management and application processing. Software license requirements will be determined by the number of users of the application.

Implementation - Walk Before You Run
Providing access to GIS data and applications can be problematic. The web-enabled GIS software applications available on the market today are all relatively new. There are often bugs in the software that can result in some unanticipated set backs. Further, applications developed for the internet often require several iterations of modification before the desired performance is achieved. It is recommended that an internet pilot project, implemented in the form of an intranet, be performed before making data and applications available to the public. Each application should be thoroughly tested and perfected before the application is put on the net for general use. Using web-enabled applications should be a positive experience for both employees and customers. Providing access to applications and data that fhnction poorly will send a negative message to customer regardless of the positive intentions the utility may have had.

Conclusion
Web-enabled GIS applications will have a significant impact on utilities and the way they do business in the future. Proper planning and implementation of internet/intranet applications will result in numerous benefits for utilities and their customers. Although in the early stages of application development, many utilities have plans for implementing dynamic maps both externally on the internet for their customers, and internally on their intranets for use by employees.

References

ter Haar, P., 1997, Intemet-based GIS - The Next Step on the Desktop, GIM, Vol. 11, No. 6, pp. 6-9.