Www.csiro.au How do you want that data? Spatial information models and web interfaces Simon Cox...

www.csiro.au

How do you want that data? Spatial information models and web interfaces

Simon Cox

CSIRO Exploration and Mining

7 September 2005

Datamodels and interfaces

Outline

Geospatial datamodels

OGC interfaces


Fields vs. objects

classic geology“Feature” viewpoint

classic earth-observations“Coverage” viewpoint


1. Classic geometry-centric GIS approach

One shape per feature …

Really an implementation strategy, downplaying the business object

Tenement

Points, lines and polygons are primary objects

Annotated with a set of attributes, often a row of scalar values

layer name => semantics


2. Conceptual object model: features

Digital objects correspond with identifiable, typed, objects in the real world

mountain, road, specimen, event, tract

Feature-type characterised by a specific set of properties

each property is constant on the feature

spatial values are just another property

multiple geometries possible, e.g. scale dependence for single feature

Properties include associations between complex objects

i.e. the value of a property may be a complex object

association-role == property


3. Spatial function: coverage

(x1,y1)

(x2,y2)

Variation of a property across the domain of interest

For each element in a spatio-temporal domain, a value from the range can be determined

c.f. features, where each property is constant

Discrete or continuous domain

Domain is often a grid

Arc/Info “coverage” == multi-geometry domain, attribute-table for each element


Cross-sections through information

Specimen Au (ppm) Cu-a (%) Cu-b (%) As (ppm) Sb (ppm)

ABC-123 1.23 3.45 4.23 0.5 0.34 A Row gives properties of one feature

A Column = variation of a single property across a domain (i.e. set of locations)


4. Data capture: the observation model

Description of observation event provides data acquisition “metadata”

map from feature to property-estimate

supports quality/confidence assessment, data processing


Cross-sections through information


ABC-123 1.23 3.45 4.23 0.5 0.34 A Row gives properties of one feature

A Column = variation of a single property across a domain (i.e. set of locations)

A Cell reflects the result of a single observation


Section view

Sometimes they appear together

Properties

Map view Survey

Continuous logs

Intervals

Horizons

Point observations

Position is 1-D arc-length from collar

Collar (Point Property)

Shape (Curve Property)

Samples


Several views of the same information


ABC-123 1.23 3.45 4.23 0.5 0.34

Result/Observation view

Used for:

Quality/confidence assessment

Result calibration

Database insertion and update

Feature view

Assembled by:

Aggregation of multiple Observation/result having same featureOfInterest

Used for:

Object descriptionCoverage view

Assembled by:

Aggregation of multiple Observation/result having same observedProperty

Used for:

Property variation

Pattern/anomaly/feature detection


OGC Information Service interfaces

Web Map Service

Catalog Service

Web Feature Service

Web Coverage Service

Sensor Observation Service

Web Processing Service


Open Geospatial Consortium - Web Feature Service

GML WFSServer

Data-source organised for custodian’s requirements

Community-specific GML application language

TigerGML, LandGML, O&M, XMML, CGI-GML, ADX, GPML, CSML, MarineXML etc

private public boundary

WFSClient

HTML


Web Feature Service - operations

GetCapabilities

DescribeFeatureType

response:

GML schema for feature-type

GetFeature

request parameters:

Feature type

Property value

response:

Collection of feature instances of requested type

i.e. operation signature matches Feature-property information model


Web Coverage Service - operations

GetCapabilities

DescribeCoverage

response:

domainSet – spatial and temporal domains

rangeSet – component axis descriptions (though merely text strings …)

GetCoverage

request parameters:

domain subset

range subset – selected axes

i.e. operation signature matches Coverage/domain-Coverage/range information model


Sensor Observation Service - operations

GetCapabilities

DescribeFeatureOfInterest

DescribeSensor

GetFeatureOfInterest

GetFeatureOfInterestTime

GetObservation

GetResult

…

i.e. operation signature strongly based on Observation information model


Several views of the same information


ABC-123 1.23 3.45 4.23 0.5 0.34


Data re-use

WFSClient

WFSServer

multiple views of same data

(features)

SOSClient

SOSServer

(observations)

WCSServer(coverages)

WCSClient


Combining with observation service

WFSClient

WFSServer

WFS/SOSClient/Server

(orchestration)

WFSClient

(simulation)

(mapping)

WFSClient (analysis &reporting)

SOSServer

Sensor

BPEL?


Standard transfer format allows multiple data sources

WFSClient

WFSServer

WFSServer

B

WFSServer

C

Datamodels and interfaces PIRSA DOIR GA

http://cgsrv3.arrc.csiro.au/seegrid/savedapps/filter

Three servers, one map

Mapping client


Value-adding chain

Observation/result

estimate of value of a property for a single specimen/station/location

data-capture, with metadata concerning procedure, operator, etc

Coverage

compilation of values of a single property across the domain of interest

data prepared for analysis/pattern detection

Feature

object having geometry & values of several different properties

1. classified object, snapshot for transport

geological map elements

2. object created by human activity, artefact of investigation

borehole, mine, specimen

www.csiro.au

Thank You

CSIRO Exploration and Mining

Name Simon Cox

Title Research Scientist

Phone +61 8 6436 8639

Email [email protected]

Web www.seegrid.csiro.au

Contact CSIRO

Phone 1300 363 400

+61 3 9545 2176

Email [email protected]

Web www.csiro.au

Www.csiro.au How do you want that data? Spatial information models and web interfaces Simon Cox...

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