information viewpoints and geoscience service architectures

Information Viewpoints and Geoscience Service Architectures

Simon Cox

Research Scientist

13 December 2007

CSIRO AGU Fall 2007 – IN43C-07 Cox

Outline

• Key viewpoints for earth science information• Feature, field, observation

• The value-adding cycle• Mapping the viewpoints to OGC services and chains


Fields vs. objects

classic geology: “feature”

classic earth-observations:“field” or “coverage”


Conceptual object model: features

• Digital object corresponding with identifiable, typed, object in the real world

• mountain, road, specimen, event, tract, catchment, wetland, farm, bore, reach, property, license-area, station

• Feature-type characterised by specific set of properties

• Specimen• ID (name)• description• mass

• processing details• sampling location• sampling time• related

observation• material• …


Mapped features


Spatial function or field – “coverage”

(x1,y1)

(x2,y2)

• Variation of a property in domain of interest• Property may be multi-component• Domain is often sampled on a grid

• Domain extent is scoped by shape/lifetime of feature of interest

• Range-type is scoped by type of feature-of-interest


Different cross-sections through same dataset

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 summarizes the properties of one feature

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


Assignment of property values

• For each field in the table the value is eitheri. asserted

• E.g. name, owner, price, boundary (cadastral feature types)

i. observed/estimated• E.g. colour, mass, shape (natural feature types)

• i.e. error is of interest


Generic pattern for observation metadata

An Observation is an action whose result is an estimate of the value of some Property of the Feature-of-interest, obtained using a specified Procedure

Feature-of-interest concept reconciles remote and in-situ observations


Three viewpoints: Feature, Coverage, Observation

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)

• A Cell reflects the result of a single observation


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


OGC Service stack

• Different information-types accessed using different interfaces• Maps – WMS• Features – WFS • Coverages – WCS • Observations – SOS

• Each interface is composed of a “set of operations”


SOS

getObservation

getResult

describeSensor

getFeatureOfInterest

Accessing data using the “Observation” viewpoint

WFS/Obs

getFeature, type=Observation

WCS

getCoverage

getCoverage(result)

Sensor Register

getRecordById

WFSgetFeature

e.g. SOS::getResult == “convenience” interface for WCS


WFS/SFS

The “Sampling Feature Service” viewpoint

WFSgetFeature

WCSgetCoverage

getCoverage(property value)

SOSgetObservation

Commondata

source

getFeature(sampling Feature)

getFeature(relatedObs/result value)

getFeature(relatedObservation)

getCoverage(result)

SensorRegister

getRecordById (procedure)

getFeature(featureOfInterest)

getObservation(relatedObs)

getResult(property value)


WFS

The “Domain Feature” viewpoint

WCSgetCoverage(property value)

getFeatureSOS

getResult(property value)

The “Observations are the most primitive” viewpoint #1– observations are property-value-providers for features

??


WCS

Accessing data using the “just the data” viewpoint

WFSgetFeature/geometry(domain exent)

getCoverageSOS

getResult (lots of ‘em)(range values)

The “Observations are the most primitive” viewpoint #2 – observations are range-value-providers for coverages


Key points

• Earth scientists use multiple viewpoints onto their data• These can be reconciled through a robust data model• Service interfaces to the different viewpoints can be composed

in various ways, based on a simple set of OGC components

Contact UsPhone: 1300 363 400 or +61 3 9545 2176

Email: [email protected] Web: www.csiro.au

Thank you

Exploration & MiningSimon CoxResearch Scientist

Phone: 08 6436 8639Email: [email protected]: www.seegrid.csiro.au


RockSample-A :Specimen

DensityItA :Observation

Density :Phenomenon

Densitometry :ObservationProcedure

2610 kg/T :Measure

2006-11-23 :TM_Instant

Leederv ille, WA :Location

RockSample-B :Specimen

DensityItB :Observation

2580 kg/T :Measure


West Leederv ille, WA :Location

+time+result

+procedure+observedProperty

+featureOfInterest

+samplingLocation

+density

+samplingLocation

+time


+featureOfInterest

+result

+density

ProbeItA :Observation

Material :Phenomenon

Microprobe :Observ ationProcedure

MineralDistribution :CV_Coverage

2006-11-24/2006-11-26 :TM_Period



+observedProperty +procedure

+result+time

+material

+featureOfInterest

+samplingLocation RockSample-A :Specimen

2610 kg/T :Measure


+density


DensityItA :Observ ation

Density :Phenomenon


2610 kg/T :Measure



+featureOfInterest


+result

+density

+time


2610 kg/T :Measure


RockSample-B :Specimen

2580 kg/T :Measure

West Leederv ille, WA :Location

+density

+samplingLocation

+density

+samplingLocation

ProbeItA :Observation

Material :Phenomenon

Microprobe :Observ ationProcedure

MineralDistribution :CV_Coverage

2006-11-24/2006-11-26 :TM_Period


DensityItA :Observation

Density :Phenomenon


2610 kg/T :Measure




+result+time

+featureOfInterest

+material

+featureOfInterest


+result

+density

+time

+samplingLocation

MineralDistribution :CV_Cov erage


2610 kg/T :Measure


+material

+density

+samplingLocation

Observations, features and coverages

Feature summary

Property-valueevidence

Multiple observations one feature, different properties:feature summary evidence

A property-valuemay be a coverage

Same property onmultiple samplesis a another kindof coverage

Multiple observations different features, one property:coverage evidence


WFS Operation

WFS-Client WFS

GetCapabilities()

Capabilities()

DescribeFeatureType(FeatureType)

XML Schema()

GetFeature(FeatureType, FilterExpression)

Feature Collection ()

GetGmlObject(ObjectID)

Object()

Transaction(...)

TransactionResponse()

Name:Package:Version:Author:

WFS-S1OWS1.0Simon Cox


Multiple interfaces to same information?

• SOS::GetObservation == WFS::GetFeature(type=Observation)• SOS::GetResult == WCS::GetCoverage• SOS::DescribeSensor == WFS::GetFeature(type=Sensor)

or CSW::GetRecordById

• “Profile” generic operations• fix one or more parameters


Service profiles

• WFS is “soft-typed”• Any feature-type• Query scoped by response model

• Strong-typed service = profile of generic service-type• Limit response model

• SOS = WFS(feature-type=Observation)• GeoSciML-service = WFS(feature-type=gsml:*)• Spectral Data Service = WCS(domain=wavelength)

• Limit query model• Queriable properties = subset of response model

• Conformance-levels?• Level 0 – spatial queries only• Level 1 – only these props• Level 2 – complete WFS

information viewpoints and geoscience service architectures

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