GeoSciML- a geoscience specific GML application to support interchange of

geoscience information CGI Interoperability Working Group

Presented by Stephen RichardArizona Geological Survey/

U.S. Geological Survey

Objectives of presentation:• What is GeoSciML?• How was it developed?• What does it look like?• How do I use it?

What is GeoSciML

• GeoSciML is an XML-based Geography Markup Language (GML) application

• Based on Open Geospatial Consortium (OGC) standards

• Framework for application-neutral encoding of geoscience thematic data and related spatial data.

History• Meeting in Edinburgh, Nov. 2003 to discuss problem:

– Requirement to provide and exchange data in electronic format

– Data from each source in a different format so difficult to integrate

• Representatives of geological surveys from: UK, Canada, US, France, Germany, Netherlands, Australia (CSIRO),

Sweden, Japan, Czech Republic, Poland, Ireland, Finland

• Set up Interoperability Working Group under auspices of new IUGS CGI to address problem

Objectives for working group

• Develop a conceptual geoscience data model

• Map this to an interchange format• Develop testbed(s) to prove /

demonstrate use of the interchange format

• Assess vocabulary requirements

Approach:• Draw on previous work

– Existing geoscience data models– Existing markup language specs

• Face-to-face meetings and Twiki• Start with main components of geological map and

borehole data (geological unit, Earth material, faults, contacts, and their defining concepts)

• Expand later to other geoscience domains (extend model or import namespaces?)

Mostly piggyback on ongoing activities

Participants• GeoSciML development

team:– Eric Boisvert (GSC)– Boyan Brodaric (GSC)– Tim Duffy (BGS)– Simon Cox (CSIRO)– Bruce Johnson (USGS)– John Laxton (BGS)– Steve Richard (AZGS-USGS)– Jean-Jacques Serrano (BRGM)– Bruce Simons (GSV)– Lars Stolen (SGU)– Leslie Wyborn (GA)

Process

• Review existing models• Develop a conceptual data model and from

this derive logical data model in UML• Map this to XML for interchange using

OGC GML standard (UML2GML profile) • Use web services for delivery

NADM C1: North American Geologic Map Data Model

• Conceptual—UML diagrams and text; implementation not specified

• Scope:– Materials—rock,

mineral, sediment– Bodies of material

(geologic units)– Structures– Processes, Events– Relationships

XMMLObservation and MeasurementOGC draft standard (OGC® 05-087r4)

Scope:•Site (includes boreholes)

•Sample

•Observation

•MeasurementBasis for documenting provenance of data

Interoperability via web service

GA

BGS

USGS

GSC

USGSschema

BGSschema

GAschema

GSCschema

GA

BGS

USGS

GSC

GA

BGS

NGMDB

GSC

wrapper

wrapper

wrapper

wrapper

wrapperWebServices Client

Communication between service providers and clientstakes place using XML mark up.

Use of standard markup language means schema mapping only needs to be done once

Web service only implements interface for standard markup input and output

Data InterchangeExtract Load

Interchangeschema

GSCGSCGSCGeoSciMLwrapperUSGSUSGS NGMDB GeoSciML

wrapper

Data InterchangeEach data provider and consumer implements a wrapper that maps

xml to and from local schema to interchange schema;Use of standard means this schema mapping

only needs to be done once.Users must still resolve semantic (terminological) differences in

datasets that do not use a common vocabulary.

Transform

GeoSciML v2• Document content—collection of:

– Geologic unit– Geologic structure– Mapped feature (lines, polygons)

– Earth material description (rock, unconsolidated)

– Vocabulary (Collection of terms with definitions)

– Events– Relationships

Geologic Unit• Classifier– link to lexicon, identifies described unit• Body morphology– shape of unit as 3-D body• Color— color of unit in exposures• Composition category– general composition character of unit; chemical or petrographic• Outcrop character — nature of outcrops formed by geologic unit • Parts – aggregate geologic units• Composition -- lithologic constituents• Metamorphic description — facies, grade, peak P, Peak T, protolith• Unit thickness• Age, geologic history — one or more genetic events in history of unit• Bedding character — pattern, style, thickness• Physical properties — density, magnetic susceptibility, porosity, permeability• Weathering character — degree, products, process, environment• Related geologic units and structures – soft typed relationships

Geologic structure• Subtypes:– Shear displacement structure, fault, ductile shear

zone– Fracture, joint– Contact – boundary between units

– Fold, Fold system – collection of related folds

– Foliation, layering– Lineation– Non directed structure – soft typed class to represent

sedimentary and igneous structures

Faults• Displacement-- collection of displacement

events– Each has age, process environment, movement

type (strike slip, normal…) and sense (normal, right…),

may have slip or separation• Segmentation, aggregationsegments faults

Fault system

Structure orientation

• Planar and linear orientation elements• Allow numeric measurement, numeric

range, or qualitative text specifier (e.g. steep, northerly)

• Planar orientation has polarity (facing)• Linear orientation may be directed

Earth Material

• Mass noun, not a feature• Subtypes:

– Mineral– Inorganic fluid (water..)– OrganicMaterial

– CompoundMaterial — material that is an aggregation of constituent parts

– Rock, – UnconsolidatedMaterial– MaterialFossil

Rock, Unconsolidated material parts• Each part:

– role, proportion, type– represents aggregation of particles of some

type, which may have a grain size and shape description

– composed of some Earth Material• Relationships between parts (overgrows,

replaces…)

Rock, Unconsolidated material properties

• Color• Composition category – terms for chemical or petrographic character

• Genetic category – term to characterize geologic history of material

• Consolidation degree• Lithology classifier – kind of material described, from controlled

vocabulary• Physical properties — density, magnetic susceptibility, porosity,

permeability• Metamorphic description – facies, grade, peak P, peak T, protolith

• Fabric description – type, text description

• Particle geometry – grain size, sorting, shape, aspect ratio

http://www.cgi-iugs.org/

Cobre Ridge Tuff (Jurassic)- Drewes [1997] divided into upper and lower welded tuff (units Juw and Jlw of Drewes, 1997) separated by sandstone of Arivaca (Jsa). Described as porphyritic rock with 10-25 % phenocrysts 2-7 mm in size, in cryptocrystalline groundmass with some relict devitrified glass and shards. Phenocrysts included quartz (3-8%), albitized plagioclase (2-10%), potassium feldspar (possibly sanidine in some rocks) (2-10%), biotite (1-5%), and trace magnetite, apatite, and zircon. Lithic fragments and fiamme are sparse. Rock weathers slightly platy, with foliation oriented parallelt o bedding in sandstone of Arivaca. Fiamme and shardy structure are usually visible without a microscope, but in some rocks they are

nebulous features. Probably more than 500 m thick.

Metadata• Uses ISO 19115• Feature Level or Dataset level• Extensive capability to record

– Data processing steps– Source citation– Spatial reference– Maintenance information– Use constraints, availability, point of contact….

Linked packages• Observation and measurement

– Detailed data acquisition metadata, process, equipment, observation conditions

• Sampling– Site, Borehole– Specimen

• Assay data exchange– Specimen splits– Chain of custody

• Geologic Time– GSSP– Time ordinal era

What is “an Observation”• Observation -- a procedure applied at a

specific time and place• Result -- an estimate of some property

value• Observed property is bound to a feature

of interest

Observed property• Sensible phenomenon or property-type

– Length, mass, temperature, shape– location, event-time– colour, chemical concentration– count/frequency, presence– species or kind

• Expressed using a reference system or scale– Scale may also be ordinal or categorical– May require a complex structure

• “Sensible”, but not necessarily physical …

Feature-of-interest• The observed property is associated with

something– “Location” does not have properties,

the thing at a location does– The property must be logically consistent with

the domain feature-type• E.g. rock sample->density, pixel->colour, city->

population, ocean-surface->temperature

• … Observation-target

Procedures• Instruments & Sensors

– Respond to a stimulus from local physics or chemistry

– Intention may concern local or remote source (brunton compass vs. camera)

– Sample (feature of interest) may be in situ or re-located

• Observers, algorithms, simulations, processing chains …

• “estimation” process

Observation

+ quality: DQ_Element [0..1]+ responsible: CI_ResponsibleParty [0..1]+ resultDefinition: CharacterString [0..1]

Procedure

AnyFeature

PropertyType

Event

+ eventParameter: TypedValue [0..*]+ time: TM_Object

Any{n}

+observedProperty

+propertyValueProvider

0..*

+featureOfInterest1

+generatedObservation

0..*

+procedure

1

+result

A common pattern: the observation model

• An Observation is an Event whose result is an estimate of the value of some observedProperty of the featureOfInterest, obtained using a specified procedure

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

Proximate vs. Ultimate Feature-of-Interest

• The proximate feature-of-interest may sample a more meaningful domain-feature– Rock-specimen samples an ore-body– Well samples an aquifer– Sounding samples an ocean/atmosphere column– Cross-section samples a rock-unit– Scene samples the earth’s surface

• i.e. two feature types involved, with an association between them

Sampling featuresObserv ation

SamplingFeature

AnyFeature

StationSpecimen

GeologicUnit

Profile

+relatedObservation

0..*

+sampledFeature

1

GeoSciML use cases• Data publication/interchange

– Geologic maps– Borehole geology– Specimen descriptions– Earth material substrate for soil map

• Input/output format for applications– 3-D models– Mineral resource assessment– Hazard assessment

• Shared schema for specifying properties of interest – Queries– Data discovery– Symbolization

What GeoSciML does not do• Create information• Determine fitness for use• Resolve semantic conflicts • Not efficient for online display of maps• Record cartographic portrayal information

Communication protocols

Data language

Data structure

Data content

interoperability

GeoSciML

Ontology (shared concepts)

Geoscience

GML, XML

WFS, WMS, WCS

OpenGIS

Interoperability Stack

TCP/IP, hardware protocols, etc

Semantic interoperability:

SAME?SAME?

Use cases– display map, query one feature, return

attributes in GeoSciML– query several map features, return

GeoSciML file for download– reclassify map features based on

GeoSciML GeologicAge or Lithology

Activities: Testbed 2

Results• Use-case 1: query feature

– Query one map feature (e.g. a geologic unit) and return GeoSciML

Current activities• Concept definition task group mission

– Specify concept space for GeoSciML attributes– Define categories that cover each space and assign

language independent identifiers to each category• Melbourne, Australia Sept. 2007 – test bed 3 use

cases

Learn more, get involved: https://www.seegrid.csiro.au/twiki/bin/view/CGIModel/GeoSciML

or Google ‘GeoSciML Twiki’

Concept Definition Task Group

• Specify concepts and property values required to populate GeoSciML document instances

• Language independent identifiers allow association of these with different words for different communities

In Closing• Significant challenges

– Service definitions – Development of wrappers for mapping to/from

interchange format(s)– Semantic interoperability-- shared

vocabulary/ontology or software semantic mediation

Why GeoSciML?Geoinformatics!

• Discover information resources• Utilize existing data• Enable automated workflow utilizing

geoscience information– Decision making; Research; Education

The End

Data TierData sources are heterogeneous in

schema and semanticsData sources are independently

managed

Middleware

Web servicesA web service may be client for one or

more other services.Web services use XMLfor communication

(syntactic interoperability), but eachclient and data source may usedifferent schema.

ClientHuman userClient side may be an automated

applicationfor further processing ora human information user. Clientsoperate in local environment

Query construction,Result viewing

Automated processQuery construction,

Result viewing

Requirements to set up service:• Data in vector digital form• Web server connected to the internet• Internet map server that can access data.• Software to process OGC Web Map Service

(WMS) and Web Feature Service (WFS) requests

• Software to convert hosted data into GeoSciML based on service requests.

Related Work

• CML – components for geochemistry

• Water ML – components for hydrogeology

• Mineral Occurrence model – components for economic geology

• DIGGS – Data interchange for geotechnical and geoenvironmental specialists

Application to a domain

• feature of interest– Feature-type taken from a domain-model

• observed property– Member of feature-of-interest-type

• procedure– Suitable for property-type

Observation

+ quality: DQ_Element [0..1]+ responsible: CI_ResponsibleParty [0..1]+ resultDefinition: CharacterString [0..1]

Procedure

AnyFeature

PropertyType

Event

+ eventParameter: TypedValue [0..*]+ time: TM_Object

Any{n}

+observedProperty

+propertyValueProvider

0..*

+featureOfInterest1

+generatedObservation

0..*

+procedure

1

+result