Nov. 2001 Copyright Galdos Systems Inc. November 2001 Geography Markup Language Enabling the...

Nov. 2001Copyright Galdos Systems Inc. November 2001

Geography Markup Language

Enabling the Geo-spatial Web


Galdos ?

XML specialists for Geo-spatial !

Originators of GML

Developer of GML Products & Services

Galdos Systems Inc. Vancouver, Canada


Geo-spatial World Wide Web

What is it ?

How does GML enable it ?


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!!


Legacy Data Development

Like Building a Music Web

Site

Go to the Library

Record Some Music

Find & Write Some Text

Music Web Site

Integration


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


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


GML in Action

GML Data Store

Styling Engine

Browser with SVG Plug-in

XSLT

GML

SVG


GML - Builds on W3C Standards


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


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


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


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


GML: The Linking Part

getData()

GML Data

Geographic Data Server (OGC WFS)

Links to other geographic data


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


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.


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!


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!


<tc:ServingArea gml:id = “Biloxia”> <gml:extentOf>

<gml:Polygon srsName=“..”> <gml:outerBoundaryIs> <gml:Ring>

<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



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


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


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



<tc:ServingArea gml:id = “Biloxia”> <gml:extentOf>

<gml:Polygon srsName=“..”> <gml:outerBoundaryIs> <gml:Ring>




<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



GML Ideas

GML core schemas

Shared schemas for

a vertical domain (e.g.

utilities)


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.


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.


Information Communities

Common Geographic and Geometric Constructs

Location Service Constructs

Network Constructs

Transportation Constructs

Numbers Strings

Logistical Constructs

Outside Plant Constructs


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


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


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


Geo-spatial World Wide Web

Information Communities with Shared Schemas

Shared Data – linked into a web

Web-based Services based on common

types


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 !


[email protected]

More Info ??


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!


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.

Nov. 2001 Copyright Galdos Systems Inc. November 2001 Geography Markup Language Enabling the...

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