Metadata is like onions...

Entrance door

Description of data

Content

Map documents

Layers

Geodatabase datasets

Non-spatial table

Data about 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
• ......

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?

(...)

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

• Knowledge of reality


• Metadata


• Management of relational databases


• Tools and techniques in Geographic Information Systems

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.

In summary, spatial data should be:

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

• 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 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.

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

ISO 19115 and INSPIRE Standard

We can have:

Desktop editors

Online editors

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

Relevant information

from several projects

Example of ArcGIS visualisation

Metadata Editor

GI Profile

Obsolete

Example of a catalogue of data for public access

• 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)

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

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

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

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)

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.

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.

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)

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)

Practical exercise 2

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?

• 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?

Practical exercise 3

Search for data using a global geoportal

It shall have the possibility to:

• Finding WMS, WFS

• Display information in viewer

• Display metadata