Citizen observatories are community-based environmental monitoring and information systems which can be used as a policy making and evaluation instrument for improving the quality of life of citizens


The sheer number of sensor-enhanced mobile devices combined with their user’s mobility led to the establishment of participatory sensing.


Participatory sensing relies on individuals, acting alone or in groups, along with their personal smartphones to systematically monitor personal information and/or environmental data.

DISCOPAR is a web-based configurable citizen observatory tool. DISCOPAR enables users to set up their own observatory to collect, analyse and evaluate a specific type of data. Each observatory has a corresponding mobile app, which the creator of the observatory can design using a visual programming language. Within each observatory, users can deploy campaigns to aggregate data for a particular goal and/or concern. Campaigns are only interested in a sub-set of the observatory data, and can describe how the observatory data should be filtered, processed, and aggregated through a similar visual programming language. DISCOPAR is implemented using a component based framework inspired by flow-based programming, that provides a component library for constructing a large variety citizen observatories.


To create a new observatory, you simply have to specify the name and purpose of the observatory, along with an image that will be used as icon for the mobile app.

Each citizen observatory has a custom web page associated with it. This web page consists of a dashboard that grants the observatory creator access to:

  1. The mobile app builder, enabling the creating of a customised data gathering app for the observatory

  2. The observatory component graph, which can be modified to add extra server-side data processing and/or monitoring features to the observatory

  3. A monitoring page that provides statistics and real-time information about the observatory and the participants thereof

Additionally, this web page provides access for all users to the mobile app, the observatory data browser, and to the campaign designer


The observatory creator is responsible for assembling a mobile app using predefined building blocks. These building blocks, or components, can be used to capture the required data from participants using a mobile client.

The app builder consists of four main elements:

  1. The component library menu, granting access to a wide variety of components

  2. The designer canvas, where components can be connected to 'program' the mobile app.

  3. A live preview of the mobile app, enabling you to test the app during the development process

  4. A form builder, which used a drag-and-drop interface to design questionnaires


Each user of the platform is allowed to deploy one or more campaigns in each of the citizen observatories that are available. Campaigns can be deployed in an observatory to aggregate data for a particular goal and/or concern.

To create a campaign, you must describe the sub-set of data that you are interested in through a set of constraints, as well as how the data should be aggregated and visualised.

Creating a campaign results in the creation of a dedicated web page where users can retrieve information about the campaigns purpose, browse the data and visualisations of the campaign, etc.

This campaign web page also grants the campaign designer access to the campaign builder, which consist of two parts:

  1. A geographical constraint editor, to indicate what area(s) are of interest to the campaign

  2. A campaign component graph editor, to specify how data uploaded from the mobile app should be processed.


DISCOPAR (Distributed Components for Participatory Campaigning) is being developed as part of the research project:

A Cloud-Based Reactive Infrastructure for Modelling Participatory Sensing Campaigns - Towards Mapping Mobility Parameters in Brussels

This project is funded by Innoviris, the Brussels Institute for Research and Innovation.
DISCOPAR is developed at the Software Languages Lab of the Vrije Universiteit Brussel.


Got questions about DisCoPar? Feel free to contact us at: info@discopar.net


DisCoPar: Distributed Components for Participatory Campaigning, The Sixth IEEE Workshop on Pervasive Collaboration and Social Networking (PerCol'15), 2015, Jesse Zaman and Wolfgang De Meuter
A Flow-Based Programming Framework for Mobile App Development, The Third International Workshop on Programming for Mobile and Touch (PROMOTO '15), 2015, Jesse Zaman, Lode Hoste and Wolfgang De Meuter