Download Feature - SEEGrid

How do you want that data?
Spatial information models and web interfaces
Simon Cox
CSIRO Exploration and Mining
7 September 2005
www.csiro.au
Outline
Geospatial datamodels
OGC interfaces
Datamodels and interfaces
Fields vs. objects
classic earth-observations
“Coverage” viewpoint
Datamodels and interfaces
classic geology
“Feature” viewpoint
1. Classic geometry-centric GIS approach
Points, lines and polygons are primary objects
 Annotated with a set of attributes, often a row of scalar values
 layer name => semantics
Tenement
One shape per feature …
Really an implementation strategy, downplaying the business object
Datamodels and interfaces
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
Datamodels and interfaces
3. Spatial function: coverage
Variation of a property across the domain of interest
(x1,y1)
(x2,y2)
 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
Datamodels and interfaces
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)
Datamodels and interfaces
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
Datamodels and interfaces
Cross-sections through information
A Cell reflects the result of a single 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)
Datamodels and interfaces
Sometimes they appear together
Section view
Properties
 Collar (Point Property)
Map view
 Shape (Curve Property)
 Survey
 Point observations
 Horizons
 Intervals
 Continuous logs
 Samples
Position is 1-D
 arc-length from collar
Datamodels and interfaces
Several views of the same information
Result/Observation view
Used for:
 Quality/confidence assessment
 Result calibration
 Database insertion and update
Specimen
Au (ppm)
Cu-a (%)
Cu-b (%)
As (ppm)
Sb (ppm)
ABC-123
1.23
3.45
4.23
0.5
0.34
Feature view
Assembled by:
 Aggregation of multiple
Observation/result
having same featureOfInterest
Used for:
Coverage view
Assembled by:
 Aggregation of multiple Observation/result
having same observedProperty
Used for:
 Property variation
 Pattern/anomaly/feature detection
Datamodels and interfaces
 Object description
OGC Information Service interfaces
Web Map Service
Catalog Service
Web Feature Service
Web Coverage Service
Sensor Observation Service
Web Processing Service
Datamodels and interfaces
Open Geospatial Consortium - Web Feature Service
private  public boundary
HTML
WFS
Client
GML
WFS
Server
Data-source organised for
custodian’s requirements
Community-specific GML application language

TigerGML, LandGML, O&M, XMML, CGI-GML, ADX, GPML, CSML, MarineXML etc
Datamodels and interfaces
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
Datamodels and interfaces
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
Datamodels and interfaces
Sensor Observation Service - operations
GetCapabilities
DescribeFeatureOfInterest
DescribeSensor
GetFeatureOfInterest
GetFeatureOfInterestTime
GetObservation
GetResult
…
i.e. operation signature strongly based on
Observation information model
Datamodels and interfaces
Several views of the same information
Specimen
Au (ppm)
Cu-a (%)
Cu-b (%)
As (ppm)
Sb (ppm)
ABC-123
1.23
3.45
4.23
0.5
0.34
Datamodels and interfaces
Data re-use
SOS
Client
WFS
Client
SOS
Server
(observations)
WFS
Server
(features)
WCS
Client
Datamodels and interfaces
WCS
Server
(coverages)
multiple views of same
data
Combining with observation service
WFS
Client
(analysis &
reporting)
WFS
Client
WFS
Server
(mapping)
WFS
Client
(simulation)
WFS/SOS
Client/
Server
Sensor
SOS
Server
(orchestration)
BPEL?
Datamodels and interfaces
Standard transfer format allows multiple data sources
WFS
Server
B
WFS
Client
WFS
Server
WFS
Server
C
Datamodels and interfaces
Mapping client
http://cgsrv3.arrc.csiro.au/seegrid/savedapps/filter
Three servers, one map
DOIR
PIRSA
Datamodels and interfaces
GA
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
Datamodels and interfaces
CSIRO Exploration and Mining
Name
Simon Cox
Title
Research Scientist
Phone
+61 8 6436 8639
Email
[email protected]
Web
www.seegrid.csiro.au
Thank You
Contact CSIRO
Phone
1300 363 400
+61 3 9545 2176
Email
[email protected]
Web
www.csiro.au
www.csiro.au