210 likes | 408 Views
Web GIS Oregon Explorer. Marc G Rempel Oregon State University The Valley Library Oregon Explorer marc.rempel@oregonstate.edu. What is the Oregon Explorer?. Natural Resources Digital Library Place-based resources Supports informed natural resource decision-making.
E N D
Web GISOregon Explorer Marc G Rempel Oregon State University The Valley Library Oregon Explorer marc.rempel@oregonstate.edu
What is the Oregon Explorer? • Natural Resources Digital Library • Place-based resources • Supports informed natural resource decision-making
Evolution of the Oregon Explorer • Basin Portals • e.g. Willamette Basin Explorer • Topic Portals • e.g. Land Use Explorer • Data Portals • e.g. Imagery Explorer • Oregon Spatial Data Library
Components of Web GIS 1. Spatial Data 2. Web Server 3. Map/GIS Server 4. Mapping Application 5. Application Enhancements (optional) MapServer example
Components of Web GIS- Spatial Data Shapefiles/ Geodatabases (ESRI) KML/KMZ (Google Earth) GeoRSS/GeoJson Web services WMS – Web Mapping Services (image) WFS – Web Feature Services (vector) WCS – Web Coverage Services (raster) Examples of Spatial Data:
Components of Web GIS- Web Server Apache Tomcat IIS (Windows) Examples of Web Servers: Web Servers provide the foundation for serving out data on the web.
Components of Web GIS- Map/GIS Servers ArcIMS ArcGIS Server GeoServer MapServer Examples of Mapping Servers:
Components of Web GIS- Map/GIS Servers • Serve spatial data via the internet. • When a request comes to the web server, the Map/GIS server application handles the request and returns a map image, attribute, geometry or downloadable data. • The Map/GIS server can also return images of legends, scale bars and reference maps. • Requests can query the spatial data and return only the data that matches the request. • Some Map/GIS servers also support geometry, geocoding and geo-processing tasks requests. (i.e. buffer queries, clipping, etc). Role of Map/GIS Servers:
Components of Web GIS- Map/GIS Servers • A Map/GIS server can have multiple services of various types. • Map service • Geoprocessing service • Geodata service • Image service • Geometry service • Geocoding service • Globe service • A map service is a specified grouping of spatial data with projection and display information defined. For ESRI, a .mxd file can serve as the source for a map service. • A Map/GIS server can allow for map services to be started and stopped. • A map service can support multiple output formats (WMS, WFS, KML) Map/GIS Server Services
Components of Web GIS- Map/GIS Servers Map/GIS Server Services: ESRI Example ArcCatalog
Components of Web GIS- Map/GIS Servers Some Map/GIS Servers expose their services via REST and SOAP APIs. REST API Representational State Transfer (REST) is a stateless protocol for leveraging representations of service data and methods. Provides a lightweight interface to access service properties and functionality through client side script. Example: http://methionine.library.oregonstate.edu/ArcGIS/rest/services SOAP API Simple Object Access Protocol (SOAP) is a protocol for creating server side classes and methods for a web service. SOAP tends to have more robust capability over REST, but can be more complicated to incorporate. Example: http://methionine.library.oregonstate.edu/ArcGIS/services/Restoration/OWRI_07_1/MapServer?wsdl REST and SOAP API
Components of Web GIS- Mapping Applications • A mapping application is a web component/page that handles requests/responses to and from the mapping server. • Typical functionality includes handling navigation panning/zooming, layer management, attribute queries and advanced processing tasks (buffer, distance calculations, etc). • ESRI WebADF/JavaScript API • Google Maps API /ArcGIS JS Extension • Google Earth API • Bing Maps API /ArcGIS JS Extension • Bing Maps Silverlight API (Microsoft) • Flex (Adobe) / ArcGIS Extension • Yahoo Maps API • OpenLayers API • ArcGIS for iPhone API coming soon. Examples of extensible Mapping Applications:
Components of Web GIS- JavaScript Class Libraries JavaScript class libraries are an optional piece of a web GIS stack that can add some dynamic user interface components such as sliders, pop-up boxes, dynamic table grids, and AJAX (Asynchronous JavaScript and XML) handling. Some popular JavaScript class libraries to consider are: • Dojo • EXT.JS • YUI (Yahoo User Interface) • jQuery • Can get from http://code.google.com/apis/ajaxlibs/
What is a mashup? • a mashup is a web page or application that combines data or functionality from two or more external sources to create a new service. • The term mashup implies easy, fast integration, frequently using open APIs and data sources to produce results that were not the original reason for producing the raw source data. • Source: Wikipedia.
A simple web mapping application • Basic HTML and JavaScript will get you a long ways.
ESRI Resource Center http://resources.esri.com/arcgisserver/index.cfm?fa=home
Examples of Mapping Mash-ups • Measure 37 Viewer • ORWAP • Oregon Restoration
Measure 37 Viewerhttp://oeapp.oregonexplorer.info/M37Viewer • Virtual Earth/Bing Maps- JavaScript API • Overlay WMS from ArcIMS • Transparency slider, legend • Create active objects (pushpins, polygons). • Uses GET_FEATURES call to ArcIMS to draw polygons. • 3D Functionality.
ORWAP- Oregon Rapid Wetland Assessment Protocolhttp://oregonexplorer.info/wetlands/ORWAP/ • Uses ArcGIS server map and geometry services. • Buffers selected point and queries intersection of layers. • Uses Virtual Earth/Bing JavaScript Extension for ArcGIS server.
Oregon Watershed Restoration Tool • ArcGIS Server 9.3 mapping backend • Bing GeoRSS Collections for basin, subbasin and watershed council layers. • REST and SOAP used for getting layer data and overlaying WMS. • DOJO javascript class library for more interactive user interface.