ogc’s foundation for inspire annex ii and iii coverage ... · new subtypes possible. ogc...

OGC Coverages :: INSPIRE 2012 :: ©2012 Jacobs U, rasdaman GmbH

OGC’s Foundation

for INSPIRE Annex II and III

Coverage Modeling

P. Baumann

Jacobs University | rasdaman GmbH

Bremen, Germany

[email protected]


Roadmap

� Motivation

� OGC Coverages• Data: Coverage Model

• Service: WCS

� Conclusion


Motivation

� Coverages represent increasingly important information source• Major contribution to Big Data

• High variability: different dimensions, contents, context, ...

� INSPIRE Annex II & III: “coverages ev’rywhere”:• heavily contain coverage types:

Elevation, Land cover, Orthoimagery, Meteo, Ocean, …

� Open Geospatial Consortium leads geo interoperability standardization• Coverages addressed since ~2001

• Stakeholder experience in all coverage app domains:

remote sensing, metocean, aviation, ...

� ...so what can OGC Coverages offer?


The Data:

OGC GML 3.2.1 Application Schema - Coverages


OGC Coverages

� Coverage = "space-time varying phenomenon“• ISO 19123 (=OGC Abstract Topic 6)

� Concrete (=interoperable) definition:

GML 3.2.1 Application Schema – Coverages• [OGC 09-146r2]

� raster + more: • Referenced / non-referenced

• curved grids, TINs, meshes, ...

• Multi-dimensional –

space, time, non-spatiotemporal axes (ex: pressure)

� Coverage-related working groups:• WCS.SWG, Coverages.DWG

5


Coverage Types «FeatureType»

Abstract

Coverage

MultiSolid

Coverage

MultiSurface

CoverageMultiCurve

Coverage

MultiPoint

Coverage

Discrete

CoverageContinuous

Coverage

as per GML 3.2.1

Rectified

GridCoverage

Referenceable

GridCoverageGrid

Coverage

all n-D !

all n-D

New subtypes possible


class GML 3.2.1 Application Schema for Coverages

«FeatureType»

Coverage

«FeatureType»

GML::Feature

«Union»

GML::DomainSet

«Union»

GML::RangeSet

«type»

SWE Common::DataRecord

rangeSetdomainSet rangeType

Coverage Definition

7

From GML 3.2.1

Has predefined hook

for metadata

ISO 19123 abstract

→ many different

implementations

possible

→ not per se

interoperable

GMLCOV concrete,

interoperable

[OGC 09-146r1]

Harmonized with SWE


Inset: INSPIRE Time Handling

� OGC Coverages: time just another axis

� INSPIRE (WaterML): timseries = time slices• Issue: WaterML handles only 1 value per time slices

• image time series?

«FeatureType»Coverage

«Union»DomainSet

«Union»RangeSet

«type»DataRecord

rangeSetdomainSet rangeType


Inset: INSPIRE Interleaved Representation

� OGC Coverages: separate model from encoding

� INSPIRE: two new coverage types composed:• „as known“

• „interleaved“


Metadata

� Coverage has slot „metadata“• Embed/link any kind of metadata

� WCS will deliver this• without knowing contents


Coverage Encoding

� Pure GML: complete coverage represented by GML

� Special Format: other suitable file format (ex: MIME type “image/tiff”)

� Multipart-Mixed: multipart MIME, type “multipart/mixed”

GML Coverage

Domain set

Range type

Range set

App Metadata

GML Coverage

Domain set

Range type

xlink

App Metadata

NetCDF file

NetCDF

Domain set

Range type

Range set

App Metadata

GeoTIFF

Range type

Range set

11INSPIRE currently working on similar mechanism


The Service:

Web Coverage Service (WCS)


Web Coverage Service

� subset = trim | slice

� WCS Extensions add functionality facets: “band extraction”, scaling, CRSs,

interpolation, encoding, query language, ...

� Application Profiles establish domain-oriented bundles

13


WCS Query Extension:

Web Coverage Processing Service (WCPS)

Raster Query Language: ad-hoc navigation, extraction, aggregation, analytics

� Time series

� Image processing

� Summary data

� Sensor fusion

& pattern mining

14


WCS Application Profiles

� EO-WCS: specializes generic WCS for use on Earth Observation data• Hyperspectral imagery + image time series

• Metadata & provenance

• hierachical coverage groupings

• Mosaic overlaying,

uniform spatio-temporal retrieval

� MetOcean WCS AP initiated (MetOffice UK)

long

lat

t

15

EO Metadata Record 1

EO Metadata Record 2

[EOX]


class WCS Suite Logical View

WCS Core

Abstract Topic 6

GML Application Schema for

Coverages

SWE Common OWS CommonGML

ServiceData Model UsabilityProtocol BindingEncoding Format

WCPS

WCS-T

Range SubsettingUncertainty GET-KVP

POST-XML

SOAP

MultilingualityGeoTIFF

netCDF

JPEG2000

Interpolation

Scaling

CRSetc.

Grib

GMLJP2

EO-WCS MetOcean-WCS

REST

JSON

0..*1..*0..* 1..* 0..*

The Big Picture


Integration of OGC WCS and SWE

� SWE O&M and SensorML (+ friends):

high flexibility to accommodate virtually any data structure

→ upstream integration

� GMLCOV and WCS (+WCPS):

one generic schema for all coverage types; scalable; versatile processing

→ downstream services

coverageserver

O&M+

SensorML

GMLCOV+

WCS

Semantic Web


Conclusion


� Scalable On-Demand Processing for the Earth Sciences• Platform: rasdaman (Array Analytics server)

� Strictly OGC WMS+WCS+WCPS; W3C Xquery; X3D

� 6 * 100+ TB databases for all Earth sciences + planetary science• Distributed query processing, integrated data/metadata search, 3D clients

EarthServer: Big Earth Data Analytics


Conclusion

� OGC coverages: a unified toolkit for all domains• Based on ISO 19123 ☺ + GML 3.2.1 → interoperable

• Space + time in an integrated, coherent fashion (CRSs!)

• Service-independent → coverages interchangeable between OGC services

• efficient encoding & interchange

• conformance testing down to pixel level

� Service model: WCS suite – from simple download to flexible queries

� INSPIRE: tremendous job modeling all Annex II+III domains!• GMLCOV-aware, in places own constructs

• More info on OGC Coverage services: ww.ogcnetwork.net/wcs


Synopsis of Coverage-Related Stds

� WCS -- simple coverage access (subsetting, transforms, ...)• EO-WCS -- specialization for timestamped EO data

� WCPS -- on-demand processing & filtering by raster query language

� WPS -- on-demand processing & filtering by server code

� SOS -- general sensor

service

acquisition

coverage

offerings,

based on

GML + formats

s2 SOS

u1...

u2

WCS

u3

WCPSs1 WCS-T

......

u4

WPS...


Sample Early WCS Based 3-D Service

[DFD-DLR, Diederich et al, 2001] based on rasdaman 22


Facing the Data Tsunami

“sensor” feeds

coverage

server

[OGC SWE]

23


[OGC SWE]

sensors feeds

Taming the Data Tsunami

Semantic

Web

24

coverage

server


Related OGC Standards


feature coverage

data

WMS

images data

meta

data

WCPS

WCS-T

WCS

FE

WFS-T

WFS

CQL

CS-T

CS-W

(Part of) The OGC Standards Quilt

• WMS "portrays spatial data → pictures"

• WCS: "provides data + descriptions; data with original

semantics, may be interpreted, extrapolated, etc.“

[09-110r3]

26


OGC WCS vs WCPS vs WPS

� WCS: simple, scalable download service

� WCPS: scalable ad-hoc processing & filtering; semantic interoperability

� WPS: any kind of functionality; syntactic interoperability

for $c in ( M1, M2, M3 )

return encode abs( $c.red - $c.nir ), "hdf" )


Coverages & WCS in Orchestrations

EO data WCS

SWE

atmospheric

data WCS

in-situ data WCS

HPC

EO

cascading

WCS

WPS


Caveat!

� ISO 19123 is an abstract model of a coverage, of which many different

implementations can be derived which are normally not interoperable

� coverage ≠ coveragecoverage ≠ coverage

ogc’s foundation for inspire annex ii and iii coverage ... · new subtypes possible. ogc...

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