CITI-SENSE Citizens’ Observatories Central Web Portal is a gateway to the Citizens’ Observatories Toolbox (COT). It provides interested parties access to the products and services, e.g., mobile apps and air quality perception surveys, and a Forum for discussion, debate and sharing of citizens own personal observations. The products and services include those based on outputs from a wealth of air quality sensor platforms.
CITI-SENSE Citizens’ Observatories Web Portal is a gateway to the numerous COs developed within the project. It is in three layers, i.e., (i) the Citizens’ Observatories (CO) central web portal, (ii) three thematic areas, and (iii web portals of the participating cities. It can be seen as the “top of a pyramid”, with the daughter data portals supplying information into it.

It includes the following seven pages:
- Home
- The project
- Citizens’ Observatories Toolbox
- Developers & Users
- Usage Examples
- FAQ
- Useful Links
- Contact Us
The front page has sections dedicated to a particular purpose. At the very top is the motto for Citizens’ Observatories, an ancient Chinese proverb which spells out their purpose. Below the main menu, the portal displays changing slogans, which remind the portal user that they can take part and make a difference.
The main page states the aim of the portal, and gives access to the COs of the CITI-SENSE project: Air Pollution Perception, Outdoor Air Quality in Cities, Indoor Air Quality in Schools, Environmental Quality in Public Spaces, Your Voice and Your Observations.

For the interested user, the web page describes the CITI-SENSE relationship to the Global Earth Observations (GEO) and gives a link to the GEO System of Systems (GEOSS).
More information is accessible using the embedded videos, hosted on YouTube. Social media platforms are presented with links as well.
