Dynamic Data Access and Dynamically Generated WMS Layers Open Source GIS Conference Ottawa June 10, 2004 11/27/2018

Introduction to Geolinking System Architecture AAFC Case and Data Flow Agenda Introduction to Geolinking System Architecture AAFC Case and Data Flow API Geolinking demonstration What’s next? 11/27/2018

Most data about geographic features is not stored in a GIS 1. Introduction Most data about geographic features is not stored in a GIS Clients by Postal Code Sales by retail outlet Butterflies by Ecodistrict Farms by Agricultural Region Students by School District It is stored in conventional databases 11/27/2018

Geographic Frameworks Data references many geographic “Frameworks” Business Telephone districts Postal / zip codes Sales regions Political Provinces / states Counties Municipalities Electoral Districts Environmental Watersheds Ecodistricts / ecoregions / ecozones 11/27/2018

The need for Geolinking There is no easy way to enable access to all this attribute information, so that it can be used in models, or mapped by a GIS No simple standard for how to encode geographic attributes or identify geographic frameworks in XML No simple way to publish attribute datasets or join databases across the Internet 11/27/2018

How Geolinking Works Geolinked Data Access Service Geolinking Service INTERNET EXTRACT JOIN Attributes Geographic Features Simple XML stream 11/27/2018

Geolinked Data Access Service (GDAS) An interface specification that describes how to provide access to geographic attributes, in XML, EXTRACT GDAS which you can then Map using a WMS Import into a database model GIS Process against another dataset View in a browser Import into a spreadsheet Attributes GDAS stream Possibly using a Geolinking Service 11/27/2018

Geolinking Service (GLS) An interface specification that describes how to join a GDAS XML stream to a datastore. Web Map Database Model GIS JOIN Geographic Features GDAS stream Geolinking Service 11/27/2018

Geolinking WMS A Geolinking Service that interfaces with a WMS, to deliver real-time mapping of attributes derived from any GDAS-enabled database! WMS JOIN Ecoregion Features Geolinking Service GDAS stream Ecoregion Temperature 1 18 2 24 3 26 … … 11/27/2018

GDAS/GLS requires metadata ATTRIBUTE: Annual Farm Income units: Dollars DATABASE: Census of Agriculture owner: Statistics Canada version: 2001 FRAMEWORK: Electoral Districts owner: Elections Canada version: 1999 Attributes 11/27/2018

Geolinking requires a Spatial Framework The attribute data provided by a GDAS applies to a set of geographic features (points, lines or polygons). This set of features is called the Framework. Geographic Features FRAMEWORK: Electoral Districts OWNER: Elections Canada VERSION: 1999 11/27/2018

Frameworks must be identical For geolinking to work correctly, the GDAS and GLS frameworks must be identical! A match of Frameworks is assured if the metadata in the GDAS and GLS match. Geographic Features FRAMEWORK: <Name>Electoral Districts OWNER: <Domain>ec.gc.ca VERSION: <Version>1999 11/27/2018

The benefits of Geolinking Improves the reliability of data products because the data can be obtained directly from the authoritative source one XML stream can be used to generate multiple types of products Improves the timeliness of data products because products can be instantly updated Reduces workload for data providers, because the same interface can be used to deliver information for all common uses Eliminates development times for WMS layers because layers can be created on demand 11/27/2018

What does a GDAS stream look like? <Framework> … <Dataset> <Attribute> </Attribute> <Rowset> <Row> <I>10</I> <V>36712</V> </Row> <I>11</I> <V>339164</V> <I>12</I> <V>433604</V> </Rowset> metadata * Similar to an Oracle XML dump * Similar to an HTML table data 11/27/2018

2. Status of Specifications GDAS version 0.9.1 is a discussion paper at OGC GLS version 0.9.1 is a discussion paper at OGC 11/27/2018

2. Status of Implementation GDAS and Geolinking were developed to support the CGDI. Agriculture and Agri-Food Canada Statistics Canada Geological Survey of Canada Canadian Forestry Service Environment Canada GDAS version 0.8.2 and GDAS/GLS 0.9.0 has been implemented and is fully operational at AAFC GDAS version 0.9.0 has been implemented and is fully operational at CFS 11/27/2018

Internet/Distributed Computing Platforms 3. System Architecture Data Store Backend Metadata GDAS/GLS APIs XML Streams WMS Internet/Distributed Computing Platforms Registry Provider A Provider B Wall Provider C User Fire 11/27/2018

3. AAFC Case and Data Flow GDAS Client Search Registry Get Cap Active services Visualize Registry Open registry Request Get Cap XML List of services Visualize Get Cap Get Cap list Get Data Request Produce WMS Get Data XML Request Visualize Data Get Data XML GDAS Client 11/27/2018

11/27/2018

4. API Stateless HTTP binding Follow the Request and Response roles Using GET or POST methods (to be implemented) Using Key-Value-Pair encoding Using XML encoding with SOAP stream Follow the Request and Response roles Examples: GDAS GetCapability GDAS GetData GLS GetData http://wms1.agr.gc.ca/gdas/gdas_geolinking.php?service=GLS&request=GeoLink&version=0.9.1&dName= agr.gc.ca&dataName=Ecoregion-1961-90ClimateNormals&aName=tmean_apr&aType=interval&fVersion=1&fName= Ecoregions&getdataHost=http://wms1.agr.gc.ca/gdas/&getdataApp=GetData.php 11/27/2018

5. Demo GDAS/GLS on either side of the fire wall Application for public with no restriction (Ecostrat data) Application with authentication measures Application inside of fire wall (Census data) AAFC public accessible GDAS/GLS application Open source solution e.g. Apache, PHP and Mapserver Aimed to add new OGC specifications i.e. GDAS/Geolinking Support multi-attribute streaming and mapping Dynamic WMS layer generation Utilize Distributed Computing Platforms Leverage web mapping by using GDAS/GLS client GO DEMO 11/27/2018

6. What’s next? As part of the Open Source community: Set up a Source Forge site Develop generic APIs of GDAS/GLS Integration of Open Source technology for operational use 11/27/2018

7. Questions Thank you very much! 11/27/2018