Lab Assignment 4Fall 2012
ArcGIS Server for Developing Coastal Databases

Due Date:10/25/2010

Related Materials:

Dataset:
WAGDA 2.0
Deliverables:
  • A completed answer sheet, answering all questions provided below.
  • Graphics of thematic map(s) representing a coastal geodatabase for the nonpoint source pollution
  • A screen shot of a schema diagram of the coastal geodatabase

Learning Objectives:

  • Learn about WAGDA 2.0—a spatial database indevelopment using the ArcGIS Server
  • Connect to ArcSDE Geodatabase (WAGDA 2.0) by “Spatial Database Connect” method
  • Add data from WAGDA 2.0 in a role play of Puget Sound Partnership organizations
  • Create the coastal database of spatial-temporal data for the nonpoint source pollution

Introduction:

University of Washington Libraries is upgrading its spatial data infrastructure, mainly the Washington Geospatial Data Archive (WAGDA), to an enterprise data management system with ESRI’s ArcGIS platform. The current WAGDA file-server format is a legacy method for managing and delivering digital spatial data. The current system serves from html pages with links to zipped files from a directory or points users to external locations. Accessing data sets is a process that involves locating selecting files to download one at a time, unzipping, and storing files on their local workstations (Google Search cannot index these files, which minimizes discoverability). Downloaded datasetsmight contain more data than the need of users. Finding data descriptions (metadata) requires accessing additional links and is a more cumbersome process which impedes the user’s determination of fitness for use. A centralized enterprise GIS data management system offers several improvements to current processes through a faster data search, quicker views to data, and decreases the need forthe local storage.

In addition to improving user access to currently available spatial data, an enhancement project is looking at ways in which WAGDA may expand its role as a campus-wide centralized data archive. This proposal includes broader data sharing from within the university and into the greater Puget Sound community. A beginning phase would include data currently hosted through the WAGDA site and data from other interested parties such as the Puget Sound Nearshore Ecosystem Restoration Project. Later phases would include other groups who wish to make all or sub-sets of their data available. As the use of GIS technologies continues to expand and new information is generated in the university and beyond, a central spatial data library can optimize hosting and sharing of data.

The project has set up a spatial database in development using the ArcGIS Server suite. In addition to developing a database for ArcGIS Desktop users, we are looking at additional services to make the data available in multiple and open formats. Moving forward, the project seeks information from various interested groups within the university to ensure WAGDA is appropriate to and serves their needs. This information includes a department’s GIS capabilities, its needs for both storing and sharing data, and its desired outcome from an enterprise data management scheme.

The following sections of this document describe: 1) users 2) connections, and 3) development. The overview of users explains various participant roles and functional requirements within the GIS enterprise. Various methods giving people access to data are explained with attention to how each satisfies functional requirements. Finally, a discussion of the development process reviews the project progress and addresses how WAGDA can fulfill needs of users.

[Question 1]: What is ArcGIS Server? (Hint: visit the web page of ArcGIS Server help.)

[Question 2]: What are the main components of ArcGIS Server system? (Hint: visit the web page of ArcGIS Server help.)

[Question 3]: What are included within ArcGIS Server system? (Hint: visit the web page of ArcGIS Server help.)

User Overview

  1. Use Cases

Expected users in the WAGDA enterprise areinterested groups who participate in the process from data serving to viewing. These include general UW NetID holders with the need for spatial data, participating partners on and off campus, such as UW Libraries and PSNERP. The participating roles can be broadly defined as data readers, data providers, and administrators, as explained below.

1.1 Data Readers

Data readers include any individual or group with the need to conduct read-only views and analysis of spatial data. Access may be limited to UW NetID holders with the possible addition of data partners external to UW. Available data would include a wide range of raster and vector data types covering many themes and geographies. The focus of redesigned WAGDA is on a Puget Sound Coastal Zone model emphasizing the ecological restoration and regional sustainability. Viewer profiles include students, researchers, and educators. Optimized reading methods will allow them to quickly locate relevant data, determine its fitness for uses, view it quickly in the GIS application, and save only the parts of data sets relevant to their needs. While ArcGIS Desktop is the most widely used GIS application at the university, it cannot always be assumed that users have access it. . This presents a need to deliver data that is available for other GIS platforms such as Idrisi, MapInfo, or Google Earth/Maps.

1.2 Data Providers

Data providers include groups supplying data for archiving in WAGDA. This role can involve the creation of new data sets and the spatial information. . As a research university, various departments across the University of Washingtoncampus are significant sources of spatial data, particularly with respect to the Puget Sound coastal zone. Data may be provided on disc media or through a replication of a department’s geodatabase into the WAGDA database in the ArcGIS environment.

1.3Data Administrators

The administrator group is the UW Libraries represented by Information Technology Services and the Map Collection. This role necessitates full privileges for storing, editing, viewing, and serving all data within WAGDA. The Map Collection ensures spatial data is catalogued, archived, and updated into the database as necessary. IT Services maintains servers, databases, and GIS services to ensure the enterprise is operational for all users.

  1. Functional Needs
  • Eight key functional needs of WAGDA users have been identified to ensure it yields optimal results for all users.
  • Faster data viewing – Decreasing the amount of time and number of steps needed to view data sets in a GIS enables readers to explore and use data quickly, reduces time for selecting useful data, and eliminates unnecessary downloads and the use of the local disk space.
  • Remote data analysis – As a corollary to faster data viewing, performing analysis on remote data means readers need only store analysis results or the relevant extractions of larger data sets on their local disk space.
  • Exportable – The capability of extracting and saving selected data is necessary for readers to conduct the analysis and save their results.
  • Interoperability – Providing data in non-ArcGIS and open formats is necessary to ensure the greatest accessibility and usefulness.
  • Modifiable viewer permission – Permission to view and utilize data may vary based on which data contributors want to share and to whom it will be available for view access. The ability to modify permissions allows administrators to enforce multiple permission policies laid out in data sharing agreements.
  • Complete and ready metadata – the integrated metadata is an essential component for contributors and readers in communicating the nature of data.
  • Database versions (historical and transactional) – In the ArcGIS database, previous database versions store data at certain points prior to updates that may have been made. This capability is useful for the research and analysis of phenomena that change over time.
  • Replication – Data producers within an ArcGIS enterprise can migrate their data into a primary database more quickly with the replication process while maintaining the integrity of their data schema.

[Question 4]: In your words, what are the benefits of migrating from the current WAGDA server to ArcGIS Server hosted by UWlibrary?

Part 1: Connecting to WAGDA 2.0

Data Service and Connection

The WAGDA enhancement is set up based on ESRI’s ArcGIS Server suite. It utilizes their server technology along with a database management system, PostgreSQL, to store, manage, and share data. Data sets are stored in a spatially-enabled database system, or “geodatabase”, using spatial database engine (ArcSDE).

Several methods are available to connect users to the ArcSDE geodatabase. Each method has varying capabilities in addressing functional needs. They include connections to the geodatabase, ArcGIS server publishing services, data interoperability connections, and a geoportal.

1.1 Spatial Database Connection (SDBC)

A spatial database connection is to connect users directly to the ArcSDE geodatabase when using ArcGIS Desktop/Workstation clients. These clients include ArcGlobe, ArcScene, ArcCatalog, and ArcMap. This method requires connection syntax and authentication protocol to connect with the geodatabase server and can store a connection file on the user’s workstation. This method also allows the user to connect to either the default geodatabase version or previous versions. Once connected, the user can see all data sets stored in the geodatabase.

As the data management component of ArcGIS, the ArcCatalog application enables users to quickly select and explore each data set including geometry, attributes, and metadata. The “Search” tool can quickly search on file names and metadata using keywords. One or multiple data sets can be exported directly to a user’s local workspace in one of several ArcGIS readable formats such as personal geodatabase, shapefile, or XML workspace document. Additional desktop applications, such as ArcMap, can be used to conduct the analysis or export smaller pieces of data sets.

Access permissions can be modified for each data set in the geodatabase. Data contributors and editors can utilize the spatial database connection method to participate in replication and editing processes for their data.

Connecting to ArcSDE Geodatabases: ArcCatalog and ArcMap

ArcCatalog

Open ArcCatalog.Locate and expand “Database Connections” in the catalog tree.

Double-click “Add Spatial Database Connection” to bring up the Spatial Database Connection dialogue box and fill in the following:

  1. Server: wagda.lib.washington.edu
  2. Service: sde:postgresql:wagda.lib.washington.edu
  3. Database: wagda
  4. Under “Account”, ensure “Database Authentication” is selected and enter the username and password. In this case, the username is "guest". The password is “guest” as well.
  5. As shown below, the typical connection will be to the “sde.DEFAULT” version. Selecting the “Change…” dialogue boxcan connect to either a historical marker or specific transaction date.In this lab, make sure that you set the connection as the below figure.
  1. Click the “Test Connection” button at the bottom. Then click “OK” when it is successful conncetion.

 A connection to a geodatabase will appear in the “Database Connections” folder in ArcCatalog Tree. Double-click the icon first if it has a red X on it. Expand the geodatabase and browse data in the same manner as a personal geodatabase as in a below figure.

You may wish to utilize the “Search” feature to find data you need.

  1. From the “Edit” menu, select “Search”.
  2. In “Look in”, select the folder icon and browse to, and select, your database connection.
  3. In “Name”, enter the key word with an asterisk before and after it(e.g., *road*).
  4. Alternatively, you can select the “Advanced” tab and enter a key word.
  5. You name your search by “Save as” and select “Find Now”.
  6. Your results will appear in the catalog tree under “Search”.

ArcMap:

Open ArcMap, and from the menu bar, select the “Add data” button.

Browse to “Database Connections”

Double-click the database connection.

Navigate to and highlight your desired data set(s). Click “Ok”.

To change versions:

  1. Select the “Source” tab in the “Layers” box.
  2. Right-click the SDE geodatabase and select “Change version”.
  3. You may select from available transaction or historical versions.

Analysis and geoprocessing output will be saved to your local disk.

To export an entire layer to your local disk:

  1. Right-click the layer name.
  2. Select “Data” > “Export…”
  3. Choose your desired extent, coordinate system option, and output location.

1.2Geoportal Connection(under construction)

The principal purpose of a Geoportal is to facilitate the discovery of data sources and metadata as a cataloguing utility. Contents of the geodatabase and information about available published services are provided to the user. The Geoportal may also provide a preview map with which users can select desired data layers, clip them to the desired geographic extent, and receive zipped files in their inbox.

There is another method to connect users to the ArcSDE geodatabase—GIS Server Publishing Services.

1.3GIS Server Publishing Services (under construction)

Publishing services provide additional methods to connect with the ArcSDE geodatabase while giving administrators more options in setting access privileges. These services not only serve data sets but provide options of delivering them through resources such as maps, open formats, and geoprocessing tools. Some or all of the following will be developed for the use in WAGDA depending on participant needs and capabilities.

1.3.1 Geodata Services

Publishing a connection to the ArcSDE geodatabase allows the access to it from the local network or internet. Depending on access permissions, data can be queried and extracted by authorized readers. Replication and updates are also possible for contributors and editors. A university department with new data to share would be able to utilize the Geodata Service to publish and synchronize it with the central database. Geodata services are also the basis for sharing data in open formats using Geographic Markup Language (GML) as defined by the Open Geospatial Consortium (OGC).

1.3.2 Image Services

With an image service, raster imagery such as elevation models, land cover, and orthophotos can be served and viewed seamlessly from a geodatabase. From the server, imagery can be queried, analyzed, and exported to the local disk.

1.3.3 Map Services

Map services enable sharing data from basic, non-extractable views to open format data sharing with a predefined map image. The map service can be utilized to expose a specific geographic extent or theme of data referenced in the geodatabase. This is useful for application-specific data, such as NOAAs NSPECT non-point source pollution tool, and partner data such as PSNERP.

1.3.4 Open Formats

There are four primary formats to enable interoperability in ArcGIS Server to share data depending on data type and sharing needs. Three are OGC standard formats available when publishing Geodata and Map Services. They can be viewed in any OGC format-capable GIS client. Clients access services through internet via URLs. Loading time isdepending on such as the connection speed and server loads. The ArcGIS Desktop applications on campus are all enabled with OGC clients. The fourth format offers the capability of publishing data that can be read in Google Earth (KML).

Web Mapping Service (WMS) is a strictly view-only map service for cartographic display. Feature attributes cannot be viewed or queried, nor can analysis be performed. Because it is read-only, viewers cannot export and save data.

Web Feature Service (WFS) is used to display vector data. It is suitable for performing the query, analysis, and extraction. WFS-T allows read-write access for editors working with a non-ArcGIS platform.

Web Coverage Service (WCS) is an open format for raster data. It provides the same capabilities as WFS for the query, analysis, and extraction. It is equivalent to the Image Service but uses OGC specifications.

A Keyhole Markup Language (KML) service can display published datausing online maps or 3D browsers like Google Earth. It can also be used via ESRI’s free ArcGIS Explorer as an alternative for performing basic query and analysis. There are KML readers for most spatially aware applications, as it is an open, XML-based format.

1.3.5 Geoprocessing Services

While not a connection to the geodatabase, a geoprocessing service enables users to utilize the GIS server to conduct analyses of published data. This is useful for contributors who also wish to share custom analysis tools along with their shared data. ArcGIS Explorer can also use geoprocessing services which would enable non-ArcGIS users to conduct analysis with ESRI’s data format. Examples would be geocoding of addresses using the data available in WAGDA.