Metadata and Catalogue Services

Metadata and Catalog Services


What metada and data catalogs are, their use in geographic information, their quality and where to find them in geoportals


SADL KU Leuven

WELCOME!

With the following slides and interactive material you will be able to take part in the journey to discover Spatial Data Infrastructures (SDI) its components and benefits through the observation of multiple examples and exercises. 


You can navigate through the course by pressing the navigation arrows at the bottom of each slide or using your arrow keys on your keyboard. You can move horizontally (← →) for viewing each theme and vertically (↑↓) to view extra recommended information


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Metadata and Catalog Services

#Metadata
1What is metadata?
2Resource documentation
3Data - Geographic Information
4Metadata - Key concepts
5Norms and standards for metadata
6Mandatory Elements
7Metadata — Objectives
8Exercise: Identifying Metadata
#Catalog Services
1What is a Geoportal?
2Geoportal Types
3Examples of a global geoportal
4Examples of regional and local geoportals
5Exercise retrieving information from a geoportal

01 | 01 What is metadata?

What is metadata?

Metadata is like onions...



Entrance door

What is metadata?

Description of data

Content

Map documents

Layers

Geodatabase datasets

Non-spatial table

Data about data.

Data data

Data on data or “a love note for the future”:

“The metadata, as you see, are really a note of love — it can be itself, but it is in fact a note of love for the person or maquine who after you saved him time to know what they have found.” (Scott)


Data about data

  • Data set data
  • Tool data
  • Services data
  • Lectures data
  • ......

Basic metadata example

Food in refrigerator


How do you know what each container contains?


What is the period of validity?


How to prevent dethioations?


How to store products by categories?


How to catalogue the allergens?


(...)

Resource documentation

What?— Name, fineness, small description of available resources;


Who? — Producer, owner


Where?— Coordinates, place(s)


Why?— Provision for collecting data


When?— Time information and maintenance


How?— Access to data, data lineage

Data — Geographic Information

What to do with the geographical information?

Data sharing

Easy to access

Manageability

Easy data processing


Storage of various types of data

Useful and accurate information analysis

Organisational needs

Consistency and safety


Creation Metadata

Metadata — key concepts

  • Knowledge of reality

  • Metadata

  • Management of relational databases

  • Tools and techniques in Geographic Information Systems

Metadata — Problem

Obtaining the geographical information of the different sources in the country where most of the data used by governmental institutions have a spatial nature


Gathering, mapping and cataloguing the different types of information available has a high cost


Manage large amounts of information


Norms and Standardise concepts


Metadata Creation


A lot of information is collected by different actors, repeatedly and if the information is not searchable, available and up to date, it is difficult to find


  • What does the metadata tell us about the meaning of the data?

  • What data do we care about and when was it produced?

  • Who was the producer? How was it produced and why (objectives)?

  • When produced from other data, what was the data?

  • What was the initial source of this data?


If these questions are not answered, how can we assess whether or not these data interest us? Whether or not it is correct and serves our purposes.

What metadata for what?

A short reminder!

In summary, spatial data should be:


  • Searchable
  • Accessible/widely available (but not always free)
  • Recoverables
  • Understandable
  • Usable

Norms and standards for metadata

  • Dublin core

  • Federated Geographic Data Committee (FGDC)

  • ISO * 19139/19115 (date)

  • ISO 19139/19119 (services)

  • INSPIRE * * Metadata Implementing Rules


___

* International organisation for standardisation (ISO)

* * Infrastructure for Spatial Information in Europe (INSPIRE)


Dublin Core (DC) metadata

Dublin Core is a metadata schema to describe digital objects such as video, sounds, images, text and web sites.

Source:https://pt.wikipedia.org/wiki/Dublin_Core


DC Simple:contain

15 metadata elements


CC Qualification:

Other Additional Items


Qualification of standard DC


Source:Longley et al., 2005

ISO for metadata

ISO 19139/19115

ISO 19115

(metadata creation)

TC Standard 211

(metadata standardisation)





Metadata schema

The schema consists of metadata elements.

Some are:


M — Mandatory

O — Optional

C — Conditional

It is recommended to start the mandatory metadata elements that are needed for search purposes and that are “easy” to maintain: Title, summary, reference date, language, thematic category.Metadata elements are usually grouped together.


Some optional elements are also recommended: for example, liability, online data, online services.


The table shows the key elements of ISO 19115:2003.

Mandatory elements

M4 — Metadata and Data Catalogues

Key metadata elements should answer the following questions:

Is there a set of data on a specific theme (“what”)?”,

“For a given place (“where”)?’,

“By a specific date or period (“when”)?’ and

“A contact point for learning more about or ordering the data set (“who”)?”


The use of the recommended optional elements, in addition to the mandatory elements, will enhance interoperability by allowing users to understand unambiguously the spatial data and related metadata provided by the producer or distributor. The metadata profiles of the datasets in this International Standard should include these elements.


  • The MZ profile should follow this rule...
  • Mandatory elements

    Title — The first name should not use the same name as the resource file!


    Summary — Must be concise and explain which is the data set, usually 1/3 to 1/2 of the page text.


    >Date — Date and publication data


    Language — Indicates which language the data is in


    ldentifier — A unique resource code, not automatically generated, but part of an IDE strategy for information infrastructures


    Keywords — The topic(s) covered by the dataset; you can use an existing Vocabularies (e.g. a thesauros)


    Format — Vector or raster data


    Type — Can be a data set, a data series or a web service

    Metadata

    ISO 19115 and INSPIRE Standard

    Metadata publishers

    We can have:


    Desktop editors


    Online editors



    Metadata — Objectives

    Availability of information to various organisations in the country (public or private)

    Quick access to inventory data

    Easier insertion of metadata in a national database in the Metadata management area

    Searches in a National Geospatial Data Register

    Open data creation

    Metadata advantages

    Help in:


    • Information search facility


    • Information analysis


    • Information management


    • Maintaining geographical information


    • Easy information sharing


    • Centralisation of access to information

    Metadata — getting started

    Relevant information

    from several projects

    Metadata

    Example of ArcGIS visualisation

    Data upload

    Metadata Editor

    GI Profile

    Obsolete

    Metadata

    Example of a catalogue of data for public access

    Metadata — Results in the future

    • Sharing of information between the several national bodies and departments


    • Spreading the different types of information from the country via the internet (Geoportal)


    • Effective management of information


    • Metadata sharing in a national data sharing service


    • Open data community (free of charge)

    To sum up

    Exercise: Identifying Metadata

    Practical exercise 1


    What we are looking for?

    Mozambique geomorphological Map

    Where to start?

    Search on a website containing the necessary information.

    Ex:https://esdac.jrc.ec.europa.eu/ESDB_Archive/EuDASM/Africa/index.htm


    Search Result

    Title: Mozambique Geomorphologic Map.

    Author: Mr Igor V. Bondyrev

    Publication year: 1983

    Publisher: People’s Republic of Mozambique.

    Printing: Esselte map service, Stockholm, Sweden

    Language: PT

    Geographic Coordinates: Latitude:S10°30 — S26O55

    Longitude: E30°15 — E40O50

    Scale: 2,000,000

    Keyword(s): Physical geography; Topography, geomorphology

    Spatial data infrastructures

    SDI:


    “The technology, policies, standards and human resources required to acquire, process, store, distribute and improve the use of geospatial data, services and other digital resources” (Hu & Li, 2017)


    Characteristics


    Allow for the discovery, evaluation and efficient use of geospatial data

    Data and attributes, documentation (‘metadata’), visualisation and evaluation

    Linking geospatial information repositories

    Facilitating the exchange of data between stakeholders

    Allows the data to be collected and reused for different purposes


    Functionality and search interface

    Interface... This allows?


    Consultation of the database on the basis of the information provided by the user on the web interface

    Transparency and usability

    Data input

    Presentation of results

    Quick searches/extended search (“expert mode”)

    Advanced search and main metadata components to easily assess search results


    GeoDCAT-AP — is one for platforms (European geo-portal) for spreading metadata using ISO 19115/19119 and respective XML- (ISO 19139)


    What is a Geoportal?

    Is a key component of a SDI

    ‘... the means by which users access the information available [in the IDUs]’ (Van Loenen et al., 2010)


    Some definitions and features:

    “A geportal can be defined as an entry point on the Internet or on the intranet with metadata, GI search, display, GI download, broadcasting, and in some cases, geospatial services order” (Giff et al., 2008).


    Definition: A website that serves as the starting point for accessing, on or on other sites, the wide variety of information or services organised by topics or areas of interest.

    Geoportal

    Some definitions and features:


    “They are not a repository where data are simply stored but can be considered as a one-stop-shop for geospatial data from many organisations” (Crompvorets et al., 2016)


    Used both by:


    Governmental organisations

    Private bodies



    Two different Geoportals types (or generations) (Magire & Longley, 2005)


    High-level portals (1st generation)

    Organisation and management of access to spatial information


    Web portals with applications (2nd generation)

    Simultaneous access to metadata and effective services

    Access of both SGI and browser (mobile) programmes


    Not all Geoportals has the same function

    Inform the general public (applications and utilities vs. provide raw data)





    Geoportal Types

    Geographically, there are different political levels, ranging from municipal level to global initiatives

    Geoportal often serves a specific target group or community


    But...

    Increased demand for interoperability and comparability of spatial data

    Geoportal as an access point for interoperable data and services

    Web services

    Applications

    Standards are crucial for interoperability of data and services

    Standards for file formats, projections, metadata, etc.



    Geoportal

    Geoportal

    National, regional and thematic portals and researchers related to a specific organisation or project

    Risk of publishing the same set of data several times!


    E.g.: INSPIRE

    Linking the data to the European portal is a requirement

    But the creation of a national portal is not mandatory




    ‘Complete systems [interfaces] that offer not only information but also how the user (s) are to be used efficiently’ (Van Loenen et al., 2010)


    The discovery of existing geospatial resources is one of the main functions of an geoportal.



    Geoportal

    Geoportal

    The identification and discovery of these resources is often following ‘binding and binding’ standards (e.g. Magire & Longley, 2005; HU & Li, 2017)

    The (target) data and services are published on a geoportal

    User search in Geoportal to find certain data(sets)

    The users consume the data and the services of the providers (“binding”).






    Geoportal

    Examples of actions on a geoportal:

    Search and discover (find)

    Consume (connect)


    Search and discover

    Search functionalities

    Metadata quality


    Connection to a thesaurus ( compilation of the thesaurus of a language or a knowledge area).



    Search, find, bind paradigm

    (connect)

    Example of a worldwide geoportal GEOSS

    Group on Earth Observation


    “A partnership of more than 100 national governments and more than 100 participating organisations envisaging a future where decisions and actions for humanity are transmitted through Earth observations in a coordinated, comprehensive and sustained way [...]”


    [.........] is establishing a Global Earth Observation System of Systems (GEOSS) to better integrate observation and data sharing systems by connecting existing infrastructure using common standards (Earth observations org, 2018)


    Examples of a global geoportal

    Example:

    Humanitarian aid & aid for development

    • Satellite data to identify risk areas
    • Mapping of (potential) habitats
    • Isolated settlements surrounded by tropical forests and palm oil plantations
    • Combined with census data and other sources

    (source: copernicus factsheet)

    Examples of a global geoportal

    Examples of regional and local geoportals

    Examples of regional and local geoportals

    Exercise retrieving information from a geoportal

    Practical exercise 2

    https://www.idee.es/

    Read the metadata on a regional portal (Galicia):


    • Who is the data submitter?

    • Who can I contact for questions about metadata?

    • What can I find on the map?

    • Can I consult the WMS of ArcGIS/Qgsis?

    • What format(s) are the data distributed?

    • Where data submitted are based?

    • How often is the data updated? Are data recent?

    Geoportal

    • Step by step


      • Open viewer

      • Choose the thematic maps (themes)

      • Select a map

      • Read information

      • See if metadata is available?

      • When was the last time the data was updated?

      • Is there an accessible WMS?

    Geoportal

    Practical exercise 3


    Search for data using a global geoportal


    http://geoportal.rcmrd.org/

    It shall have the possibility to:



    • Finding WMS, WFS

    • Display information in viewer

    • Display metadata

    Reference list




    • Comber, A. J., Fisher, P. F., Harvey, F., Gahegan, M., & Wadsworth, R. (2006). Using metadata to link uncertainty and data quality assessments. In Progress in Spatial Data Handling (pp. 279-292). Springer, Berlin, Heidelberg.

    • Moellering, H. (Ed.), (2005). World spatial metadata standards. Elsevier.

    • Nogueras-Iso, J., Zarazaga-Soria, F. J., & Muro-Medrano, P. R. (2005). Geographic information metadata for spatial data infrastructures. Resources, Interoperability and Information Retrieval.

    • Nogueras-Iso, J., Zarazaga-Soria, F. J., Béjar, R., Álvarez, P. J., & Muro-Medrano, P. R. (2005). OGC Catalog Services: a key element for the development of Spatial Data Infrastructures. Computers & Geosciences, 31(2), 199-209.