About Open Data
In this way society - citisenship, companies, university and any institution - can easily access to inform themselves or to create new services increasing the social value and, as the case may be, also the comercial value.
Thus, facilitate public information in open formats for everyone make use (Open Data) is to go beyond the simple process of allowing the re-use of information: it is to return public information to society and encourage them to use it for everything they want.
The possibilities are as many as ideas have the citizens. There are applications of traffic incidences advisories or other that generate interactive grafics to navigate data for specific purposes.
In fact, we can distinguish different uses: Feeding Apps (mobile applications, web, etc.), data analysis for studies on different aspect of the city, generate business from the data (infomediaries) or help in the decision making, among others.
The public administrations have much information necessary to carry out the public services that they request. But this information can be much more useful, therefore, if it is returned to citizens allowing them to reuse it for other purposes and increase the benefit of this information.
An Open Data project must work under the following objectives
- Open public data for all sectors of the institution.
- Contribute to changing the culture of re-use of public information.
- Stimulate the use and reuse of open data.
- Strengthen the initiative to open public data in other public and private institutions.
- Promote the economic fabric through this initiative.
The European Directive 2003/98 / CE, of 17 November 2003 on the re-use of public sector information established a set of rules for the treatment of reusable public information. This was amended as Directive 2013/37/UE, on June 26, 2013, and transposed at the state level as Law 18/2015, of July 9, modifying the previous Law 37/2007, of November 16, on reuse of public sector information. The Law 18/2015 aims at the basic regulation of the legal regime applicable to the reuse of documents prepared or guarded by public sector Administrations and agencies.
On the other hand, and related to the opening of public data, there are additional regulations, such as State law 19/2013, of December 9, on transparency, access to public information and good governance and Regional law 19/2014, of December 29, on transparency, access to public information and good governance. These laws aim to promote citizen participation, forcing public entities to give account to the citizens, in accordance with the principle of responsibility, their activity and the management of public resources.
About the use of data
- csv: Comma-Separated Values (CSV) files are an open document type that represents tables with columns separated by commas and rows by line breaks.
- xls: The XLS format refers to the files that the Microsoft Excel calculation program uses. The data is presented in lines and columns.
- xml: The XML (eXtensible Markup Language) files are based on a language developed by the World Wide Web Consortium (W3C) that allows defining the grammar of specific languages to structure large documents.
- zip: The ZIP format is a storage format that is used to compress documents, images or programs.
- rdf: RDF (Resource Description Framework) files are World Wide Web Consortium (W3C) specifications originally designed as metadata models. Its usual use is to give a conceptual description to the web pages.
- kml: Keyhole Markup Language (KML) files specify a set of features (place marks, images, polygons, 3D models, textual descriptions, etc.) for display in Google Earth, Maps and Mobile, or any other geospatial application software of the KML coding. Each site always has a length and a latitude.
- dat: These DAT files can be encoded in plain text format, while some DAT files are implemented with binary coding specifications.
- txt: These are files composed exclusively of text, unformatted (there is no information intended for formats or fonts).
There is a classification developed by Tim Berners-Lee, inventor of the web and director of the W3C, that allows to quantify the technological quality of the open data, by means of a classification based on stars - with values from one to five - according to the format used to represent the data.
This symbolic scheme is incremental (each state includes the previous one) and considers the following cases:
- ★ One star
- Data or documents available on the web in any format.
- Under an open, non-restrictive license.
- Unstructured format.
- The dataset or document can be viewed on the web but not automatically processed.
Examples: an image in JPG or PNG format, or a document scanned in PDF format.
- ★★ Two stars
- All of the above plus:
- Structured data or documents.
- Automatically processable.
- Proprietary format (not open).
Example: A spreadsheet in Microsoft Excel format.
- ★★★ Three stars
- All of the above plus:
- Structured and open format (non-proprietary).
Example: Spreadsheet in CSV (Comma Separated Values) format instead of Microsoft Excel.
- ★★★★ Four stars
- All of the above plus:
- Data can be referenced with persistent web addresses or Uniform Resource Identifiers (URIs).
- W3C standard and open formats are used to semantically describe the information.
Example: representation in the RDF (resource description infrastructure) model of the buildings of a public body, with its contact and location data, atomic data in which it can be accessed by web addresses (URI). Certain APIs could also be considered.
- ★★★★★ Five stars
- All of the above plus:
- Data is linked and semantically described with other external datasets to provide context to the information.
- Semantic relationships are established between linked information.
Example: In the above case, descriptions of the location of public buildings could be enriched with links to DBpedia (http://dbpedia.org). These links could include a detailed description of localities, regions, or countries and thus have direct access to socioeconomic or toponymic information of these places.
Technical excellence - five stars - is achieved when data is linked to other resources on the web through semantic mechanisms, which offer full interoperability between different systems, and allow a much more efficient reuse later.
By default, the data distributions of the Open Data BCN Service will be subject to a license CC-BY 4.0, which means that a re-use of the information (copy, adapt, process, etc.) can be carried out and distributed with the condition of citing the origin of the data.
The themess and subthemes available are as follows:
- Society and Welfare
- Town planning and Infrastructures
- Culture and Leisure
- Public sector
- Human resources
- Legislation and justice
Economy and Business
- Science and technology
On the other hand, you can also use the filters, which appear on the left side of the screen:
- Themes: Clicking on a theme or subtheme you access the list of datasets corresponding to that theme or subtheme
- Tags: Clicking on a tag you access the list of datasets with that tag
- Formats: Clicking on a format you access the list of datasets corresponding to that format
- Licenses: By clicking on a license you access the list of datasets with that license
- Frequency: Clicking on a frequency you access the list of datasets with that frequency of update
You can also download the catalog in JSON and RDF format (icon that appears on the upper right side of the dataset catalog - API Catalog -http://opendata-ajuntament.barcelona.cat/data/en/dataset)
To reuse existing data in the catalog citing the origin of the same it should be explicitly stated that they come from the Open Data Barcelona project, like this:
In the case of allowing HTML code:
This product or service uses data from the Service <a href="http://opendata-ajuntament.barcelona.cat" title="Open Data Barcelona Service">Open Data BCN</a>.
In case of only allow text:
This product or service uses data from the Open Data BCN Service (http://opendata-ajuntament.barcelona.cat).
To convert them to UTM ED50 coordinates, follow the following procedure:
1. Split them by 1,000 (or put a decimal point in the third position on the right)
2. Add 400,000 to the X coordinates (put a 4 in front)
3. Add 4,500,000 to coordinates Y (put a 45 in front)
Therefore, as an example we take these coordinates with internal format:
If we apply the procedure specified above, we obtain:
X = 30733208 / 1000 = 30733.208.
30733.208 + 400000 = 430733.208
Y = 88007.542 / 10000= 88007.542
88007.542 + 4500000 = 4588007.542
CSV files follow a standardized format and data visualization depends on the tool used. Using a text editor, the data appears on a single line separated by commas. On the other hand, in most spreadsheets and similar tools (i.e. Excel), either the format is automatically detected or options are provided to decode and display the data in a grid.
The RDF model allows you to specify metadata to describe resources of any kind (physical or virtual) on the web. This model can be represented in different formats and allows the exchange of information between automatic systems.
For example, the dataset catalog is represented in this format. This allows other initiatives at the supranational level to process and make operations to add their contents (eg, the European Data Portal performs an aggregation of European catalogs through descriptions in RDF). Our catalog is in RDF/XML format and therefore can be opened with any XML or text editor such as Notepad ++.
The WMS service defined by the OGC produces maps with spacial data referred dinamically from geographic information. With this service one cannot obtain plain data but an image that allows the representation of that data in digital format.
The WMTS service, or tiled maps service, as the WMS, provides a digital image from geographic data, but with higher answer velocity since it takes helps from the collections of tiles or portions of images already generated in defined scale intervals.
The link to a WMS service from the Open Data BCN does not provide any map directly but a URL of a map service that operates with the standard WMS (Web Map Service). This standard has to be used with a GIS software like QGIS (open license), that allows connection with the map server and navigate (movement, zoom...). Any other type of GIS software, for example ArcGIS or Geomedia, are able to work with WMS.
This service can also be used in a Geoportal that allows it, like the Geoportal of Barcelona, the portal of the Institut Cartogràfic i Geològic de Catalunya, or any other web map client.