eo/geo team response to open gis consortium catalog interface rfp george percivall...

EO/GEO Team Response toOpen GIS ConsortiumCatalog Interface RFP

George Percivall

[email protected]

February 1999

February 1999

George PercivallEO/GEO Workshop 99

Main Topics - Agenda

OpenGIS Catalog Interface RFP• Issued by Open GIS Consortium (http://www.opengis.org/)

• Issued March 1998

• OpenGIS Project Document Number 98-001

EO/GEO Team Response to RFP• Based on CEOS CIP and FGDC GEO protocols

Working to Converge Responses• Working with NIMA Catalog Team

• Combined response to OGC in May 1999

February 1999


OGC Catalog RFP - Key Requirements

• Specify standard interfaces for geospatial resource discovery and access services, independent of specific distributed computing platforms (DCPs)

• Specify specific profiles extending the general interface: CORBA, DCOM, SQL, Others

• Provide operations for creating and maintaining collections of geospatial datasets, including a metadata set and metadata entities associated with each stored dataset.

• A detailed description of how the profiles support interoperability among catalog services implemented in DCPs

• Consistent with other OpenGIS specifications

February 1999


GeoResourceDiscovery Service

Geodata AccessService

Other Data AccessService

C

Catalog

CatalogEntry

MetadataEntity

GeospatialDataset

Collection

GeospatialDataset

FeatureCollection

Feature (orCoverage)

MetadataSet

OtherDataset

Collection

OtherDataset

KEY TO ROLESC = ContainsD = Describes

C

C

C

D

D

D

C

DD

MetadataEntity

C

MetadataSet

MetadataEntity

C

(unspecified)

C

C

DD

Data Structure Classes of OpenGIS Catalog Services

February 1999


Responses to OGC RFP

CEOS Catalog Interoperability Protocol (CIP)

FGDC GEO Profile

NIMA - Geospatial and Imagery AccessServices (GIAS)

EO/GEO Team

Distributed Catalog Services (DCS)

Nov. 1998

May 1999

Joint Submission(DCS and EO/GEO)

Proposals to OGC

Existing Protocols

February 1999


EO/GEO Team

International Collaborative Effort

Industry• Blue Angel Technologies• Hammon, Jensen, Wallen and Associates, Inc. (HJW)• Environmental Systems Research Institute

Government Agencies• FGDC• NASA• CCRS• JRC

February 1999


EO/GEO Proposal

• All messages formed in XML

• Search and Retrieval messages from Z39.50

• XML passed over multiple Distributed Computing Platforms (DCPs): HTTP, CORBA, COM

• Bridges provide cross-DCP capability, without modifying XML messages

• ISO Metadata (15046-15, TC 211) as core for distributed search

• Supports search for collection and product metadata through hierarchical collections

February 1999


GILSDomain

LDAPDomain

Client

COMDomainGEO/OGC

Gateway

Proxy Client

Clearinghouse

GEO

GEODomain

GEOServer

GEOServer

GEOServer

CIPDomain

RM

RM

RMRM

CORBA/OGC Gateway

Proxy Client

CORBA

OMGDomain

CORBA/OGC Gateway

Proxy Client

SQLODBC

RelationalDatabase

SQL/ODBC

Domain

INTERNET

Cross DCP Interoperability

Proxy Client

CIP/OGC Gateway

CIP

OGC Catalog Services

XMLXML

XML

XML

February 1999


Approach to Convergence

• Two responses presented to OGC in December 98

• Desirable to merge two approaches

• Joint assessment of a single approach in January 99

• Results reported Monday (2/8) to OGC

• Second unified submission planned for May 99

Global Information Discovery

AltaVista GEO CIP DCS SimpleFeatures

Information Exploitation

February 1999


Cross-DCP Approach

IDL for CORBA

IDL for CORBA MIDL for COMMIDL for COM XML DTDs for

messaging

XML DTDs for messaging

GeneralModel (UML)

GeneralModel (UML)

February 1999


Client(or webserver)

Client(or webserver)

Catalogserver

Catalogserver

Metadataserver

Metadataserver

translatortranslator

BridgeBridge

ClientClient

Catalogserver

Catalogserver

OGCHTTP

OGCHTTP

OGCCORBA

OGCCORBACatalog

ServerCatalogServer

Browsers

Legacy

OGCCORBA

Application Servers

OGCHTTP

MetadataServer

MetadataServer

CatalogServer

CatalogServer

Catalog Service Interoperability - HTTP-CORBA Example

February 1999


Functional Decomposition of Catalog Services

Discovery Service

(mandatory)

Discovery Service

(mandatory)

Access Service

(optional)

Access Service

(optional)

Management Service

(optional)

Management Service

(optional)

DirectDirect BrokeredBrokered

Catalog Service

Catalog Service

Includes init, close functions

Services

February 1999


Conclusion

Combined Submission Feasible• Cross DCP approach using common General Model

• Messages and Object approaches

Issues of Interoperability• Compatibility with OGC Simple Features

• Query Language for cross DCP Discovery

• Metadata Model Independence

• Use of XML

Major follow-on activities• Communication of lessons learned to OGC

• Develop implementations for demonstrations

• Develop commercialization plan

• Prepare joint response documents to RFP

eo/geo team response to open gis consortium catalog interface rfp george percivall...

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