Metadata & clearinghouses

Centrum voor Geo-informatie

Metadata & clearinghouses

Madrid, 22 December 2004Joep Crompvoets

Spatial Data Infrastructures


Overview Presentation

• Metadata– what is it ?– what are the standards ?– why is it difficult to organize ?

• A few remarks on Clearinghouses (Data catalogues)


Metadata


Dsal.dat

0 0 201 0 155 0 3510 0 4575 0 30. . .. . .


Assignment

Write down 3 characteristics that you would use to describe, to someone else, a spatial dataset.


Metadata and Clearinghouses

• Metadata (data about data)

• Metadata information system

• National and International collection of metadata and data IS (clearinghouse)

• Book description (data about books)

• Library information system


Why describe spatial datasets?

Manage (storage and change) Search (content global ) Exchange (format ) Use (content details, Quality)


Target groups

Personal (storage) Own organisation (storage and

content) Other organisations (content, format,

quality, contact person)


Extent description

Target groups Functions

manage search exchange use Personal + + - - Own organisation ++ ++ ++ ++ Other organisation - +++ +++ +

++


How to describe ?

• Personal standard• Organisational standard• (inter)national standards


International standards

• America (FGDC)• Europe (CEN)• ISO (2003 world)


Identification

Quality

Spatial reference Meta-data

reference

Classification

Administr.meta-data

Overview CEN meta-data

Datadefinition

CEN meta-data standardCEN meta-data standard

CEN meta-data

Extent


NCGI data model NCGI data model


ISO Standards and Technical Reports

ISO 6709:1983 Standard representation of latitude, longitude and altitude for geographic point locations

ISO 19101:2002 Geographic information — Reference model

ISO 19105:2000 Geographic information — Conformance and testing

ISO 19107:2003 Geographic information — Spatial schema

ISO 19108:2002 Geographic information — Temporal schema

ISO 19111:2003 Geographic information — Spatial referencing by coordinates

ISO 19113:2002 Geographic information — Quality principles

ISO 19115:2003 Geographic information — Metadata ISO/TR 19120:2001 Geographic information — Functional standards

ISO/TR 19121:2000 Geographic information — Imagery and gridded data

http://www.iso.org/iso/en/CatalogueDetailPage.CatalogueDetail?CSNUMBER=13152&ICS1=35&ICS2=40&ICS3=

http://www.iso.org/iso/en/CatalogueDetailPage.CatalogueDetail?CSNUMBER=26002&ICS1=35&ICS2=240&ICS3=70





ISO 19115

• 1 General information• 2 History• 3 Data identification• 4 Spatial information• 5 Distribution• 6 Meta-information reference


Conclusions

• Describing spatial datasets with meta-data is essential to keep the data accessible in the future.

• For (inter)national exchange the use of a standard is a must.

• A problem with describing meta-data is that the personal requirements are less than the organisational requirements.



Clearinghouses (Data catalogues)


The name clearinghouse

• Banking• 1775 London

banker’s Clearinghouse

• Now national bank and IMF

• virtual market on the internet.


What is a clearinghouse ?

• A virtual market on the internet for spatial data.

• A metadata information system.• With functions to search, to view,

to download and to pay for spatial data.


Clearinghouse technical concepts

• Centralized (meta data in central database)

• Decentralized (meta data in local databases and a central query structure)

• Hybride system (part of the meta data central, part local)






Conclusions

• Large amount of spatial data will become available (by the internet) for GIS.

• Spatial data infrastructures, clearinghouses and metadata play an important role in data delivery.

• Knowledge of quality, concepts of metadata is essential to turn data into information.

Documents

Metadata & clearinghouses