Post on 19-Dec-2015
Nov. 2001Copyright Galdos Systems Inc. November 2001
Geography Markup Language
Enabling the Geo-spatial Web
Nov. 2001Copyright Galdos Systems Inc. November 2001
Galdos ?
XML specialists for Geo-spatial !
Originators of GML
Developer of GML Products & Services
Galdos Systems Inc. Vancouver, Canada
Nov. 2001Copyright Galdos Systems Inc. November 2001
Geo-spatial World Wide Web
What is it ?
How does GML enable it ?
Nov. 2001Copyright Galdos Systems Inc. November 2001
Viewpoint from Data Development
Find Data
Convert Data
Format
Integrate Data
Update/Insert Data Semantics
Select Application Technology
Up to 75-80% of Project Cost is Data Development !!
I get very little data re-use!!
Nov. 2001Copyright Galdos Systems Inc. November 2001
Legacy Data Development
Like Building a Music Web
Site
Go to the Library
Record Some Music
Find & Write Some Text
Music Web Site
Integration
Nov. 2001Copyright Galdos Systems Inc. November 2001
Web-based Data Development
Like Building a Music Web
SiteRecord Some
Music Music Web Site
Search the WebBuild some links
Integration
Let’s do the SAME thing for Geo-spatial Data
Nov. 2001Copyright Galdos Systems Inc. November 2001
Large Scale LBS Architecture
Information Infrastructure(s)
Location-Based Services
Wide area, integrated spatial data sets – the geo-spatial world wide web !
Location Services• routing• tracking• access to services• vicinity
Or other application
services
Nov. 2001Copyright Galdos Systems Inc. November 2001
GML in Action
GML Data Store
Styling Engine
Browser with SVG Plug-in
XSLT
GML
SVG
Nov. 2001Copyright Galdos Systems Inc. November 2001
GML - Builds on W3C Standards
Nov. 2001Copyright Galdos Systems Inc. November 2001
Geography Markup Language?
OGC Endorsed “Adopted Specification” (GML 2.0 passed March 2001) for encoding spatial information.A set of XML technologies for handling spatial data on the Internet.Emerging international standard for spatial data—endorsed by 200 + companies and agencies around the world.Will converge with G-XML (Japan) – additional 600 companies. Target is GML 3.0 by December 2001
Nov. 2001Copyright Galdos Systems Inc. November 2001
Geography Markup Language
XML encoding of geography (Web GIS)A schema language (based on XML Schema) for creating geographic application schemas or vocabularies.Basis for creating types (ADT) for input/output (request/response) types for web-based services..Enables complex features & feature associations
Nov. 2001Copyright Galdos Systems Inc. November 2001
GML - Enables a Geo-spatial WWW
GML => Geo-spatial schema language
GML => Geo-spatial Data sharing!
GML => Enabling of Web Services
Shared vocabularies and schemas
Shared data – create once – use anywhere !
Describe input/output message parts for web services
Nov. 2001Copyright Galdos Systems Inc. November 2001
getData()GML Data
OGC Web Feature Servers
ESRI Laser-Scan Oracle
If you can get e-mail you can get spatial data !!
Galdos
GML & Web Feature Service
Nov. 2001Copyright Galdos Systems Inc. November 2001
GML: The Linking Part
getData()
GML Data
Geographic Data Server (OGC WFS)
Links to other geographic data
Nov. 2001Copyright Galdos Systems Inc. November 2001
What is a Link ? Pointer ?
A kind of static or dynamic association between two resources.
Links can be within the same “file”Links can be thought of as semantic associations
Resource AResource B
link
Nov. 2001Copyright Galdos Systems Inc. November 2001
Geo-spatial View of Links/Pointers
Extend a feature by adding new attributes – remote geometry.Express relationships between geo-spatial features and non-spatial properties (remote properties)Express relationships between geo-spatial features.Associate datasets that cover and refine a given area.
Nov. 2001Copyright Galdos Systems Inc. November 2001
Shared GML Data
OSP Schema
Housing Units
Road Networks
Municipal Boundaries
Existing GML Based Data
Parcel Data
Other Utilities
New GML Based Data
New Telecom Application
InstanceGML Links!
Nov. 2001Copyright Galdos Systems Inc. November 2001
Telephone Attachment
s
Utility Poles
<tc:TelephonePole gml:id = “WECO1”> <tc:carries>
<tc:TelephoneDrop> …
</tc:TelephoneDrop> </tc:carries> <position xlink:href = “… UtilityPole/gml:position” /> ….</tc:TelephonePole>
<rt:UtilityPole gml:id = “P32”> <gml:position>
<gml:Point srsName = “..”><gml:coordinates> …
</gml:coordinates></gml:Point>
</gml:position><rt:UtilityPole>
Municipality
Telco
Information Infrastructures!
Nov. 2001Copyright Galdos Systems Inc. November 2001
<tc:ServingArea gml:id = “Biloxia”> <gml:extentOf>
<gml:Polygon srsName=“..”> <gml:outerBoundaryIs> <gml:Ring>
<gml:curveMember xlink:href = “ … “ />
<gml:curveMember xlink:href = “ … “ />
<gml:curveMember xlink:href = “ … “ />
<gml:Ring> <gml:outerBoundaryIs> …</gml:Polygon>
</gml:extentOf> <servedBy xlink:href = “… #SAI36” /> ….</tc: ServingArea >
Serving Area
Municipal Land Parcels
Serving Area Interfaces
sa66
sa68Serving Area Boundary
shared with municipal boundary
Information Infrastructures!
Nov. 2001Copyright Galdos Systems Inc. November 2001
GML Ideas
Resource
Value
Property
Can be another resource !!
Anything with an ID
GML 2. These are features (typed things !)
In GML Both Types and Properties are encoded as XML elements
Nov. 2001Copyright Galdos Systems Inc. November 2001
Stuff in GML namespace
GML Ideas
<abc:Road gml:fid = “t21”><abc:numLanes>4</abc:numLanes><abc:surfaceType>paved</abc:surfaceType><gml:centerLineOf>
<gml:LineString srsName =“.. “ >… <gml:LineString>
</gml:centerLineOf></abc:Road>
Properties!
Types
Nov. 2001Copyright Galdos Systems Inc. November 2001
Telephone Attachment
s
Utility Poles
<tc:TelephonePole gml:id = “WECO1”> <tc:carries>
<tc:TelephoneDrop> …
</tc:TelephoneDrop> </tc:carries> <position xlink:href = “… UtilityPole/gml:position” /> ….</tc:TelephonePole>
<rt:UtilityPole gml:id = “P32”> <gml:position>
<gml:Point srsName = “..”><gml:coordinates> …
</gml:coordinates></gml:Point>
</gml:position><rt:UtilityPole>
Municipality
Telco
Information Infrastructures!
Nov. 2001Copyright Galdos Systems Inc. November 2001
<tc:ServingArea gml:id = “Biloxia”> <gml:extentOf>
<gml:Polygon srsName=“..”> <gml:outerBoundaryIs> <gml:Ring>
<gml:curveMember xlink:href = “ … “ />
<gml:curveMember xlink:href = “ … “ />
<gml:curveMember xlink:href = “ … “ />
<gml:Ring> <gml:outerBoundaryIs> …</gml:Polygon>
</gml:extentOf> <servedBy xlink:href = “… #SAI36” /> ….</tc: ServingArea >
Serving Area
Municipal Land Parcels
Serving Area Interfaces
sa66
sa68Serving Area Boundary
shared with municipal boundary
Information Infrastructures!
Nov. 2001Copyright Galdos Systems Inc. November 2001
GML Ideas
GML core schemas
Shared schemas for
a vertical domain (e.g.
utilities)
Nov. 2001Copyright Galdos Systems Inc. November 2001
Shared GML Application Schemas
OSP Schema
Housing Units
Road Networks
Municipal Boundaries
Existing GML Application Schemas
Parcel Data
Other Utilities
New Application Schema
e.g. New Telecom Application Schema
Describes outside plant equipment –
telephone poles, SAI’s etc.
Nov. 2001Copyright Galdos Systems Inc. November 2001
Shared GML Application Schemas
Geographic Data Store
Schema Registry
Import Schema
GML Data Request & Response
Data can be stored in any manner
Users can extend GML Application
Schemas
Application Specific
Client can get back the GML Application
Schema.
Nov. 2001Copyright Galdos Systems Inc. November 2001
Information Communities
Common Geographic and Geometric Constructs
Location Service Constructs
Network Constructs
Transportation Constructs
Numbers Strings
Logistical Constructs
Outside Plant Constructs
Nov. 2001Copyright Galdos Systems Inc. November 2001
Common Geographic and Geometric Constructs
Location Service Constructs
Network Constructs
Transportation Constructs
Numbers Strings
Logistical Constructs
Outside Plan Constructs
W3C
GML
GML Application Schemas
Information Communities
Nov. 2001Copyright Galdos Systems Inc. November 2001
GML & Web-Based Services
Geo-spatial Web
Service
Client Consumer
Request Response
A routing service, a forest stand
valuation service, a geo-coding service
….
How do we find services ?
How do we access and use these services
The idea of a web-based service !
GML can be used to describe parts
of the input/output
types
Nov. 2001Copyright Galdos Systems Inc. November 2001
GML & Web-Based Services
Typing Framework
Service Type Repository
Service Instance Registry
Provide types for service definitions
Provide type definitions for
instances
GML & GML Application Schemas
Nov. 2001Copyright Galdos Systems Inc. November 2001
Geo-spatial World Wide Web
Information Communities with Shared Schemas
Shared Data – linked into a web
Web-based Services based on common
types
Nov. 2001Copyright Galdos Systems Inc. November 2001
Summary
GML => Geo-spatial schema language
GML => Shared data and associations
GML => Ennablement of Web Services
Shared vocabularies and schemas
Shared data – create once – use anywhere !
Describe input/output message parts for web services
GML enables the Geo-spatial World Wide Web !
Nov. 2001Copyright Galdos Systems Inc. November 2001
info@galdosinc.com
More Info ??
Nov. 2001Copyright Galdos Systems Inc. November 2001
Dictionary Patterns in GML
GML Data InstanceGML Data Instance
(Dictionary)
<ab:Road gml:fid = “p1”>
…..</ab:Road><ab:Road gml:fid = “p2”>
…..</ab:Road><ab:Road gml:fid = “p3”>
…..</ab:Road>…..
<de:Bridge gml:fid = “b1”> <gml:centerLineOf>
…. </gml:centerLineOf> <de:intersects xlink:href=“…#p2” />
….….
</de:Bridge>
Weakly typed references!
Nov. 2001Copyright Galdos Systems Inc. November 2001
Dictionary Patterns in GML
Used in GML for:
1. Spatial reference systems.
2. Spatial reference system support components. (GML 3.)
3. Units of Measure. (GML 3.)
4. Spatial location keywords (GML 3.)
5. Measured parameters (GML 3. & SensorML)
6. Spatial relationship terms.