Frequently Asked Questions

CitySatAir is a project that develops advanced algorithms to map urban air pollution at a high spatio-temporal resolution by combining satellite observations and ground measurements within atmospheric models.

The overarching objective of the project is to investigate how satellite retrievals of air pollutants can be better exploited for monitoring and mapping urban air quality at scales relevant for human exposure, and how this information can be disseminated operationally in relevant services.

The project operates as part of the ESA EO Science for Society Program.

The project is funded by the European Space Agency (ESA) under its EO Science for Society Program.

The project consortium is made up of the Royal Netherlands Meteorological Institute (KNMI) as the main contractor and project coordinator, alongside two project partners: the Norwegian Institute for Air Research (NILU) and Lobelia Earth, an SME based in Barcelona.

The Retina Dispersion Model is a physical, observation-based algorithm developed by Bas Mijling at the KNMI for modeling urban air pollution at high resolution using heterogeneous air quality measurements.

The system dynamically adjusts corresponding emission factors to best match observations and adjusts simulated concentration fields by spatially interpolating in-situ measurements.

It generates hourly maps of air pollutant concentrations at street-level.

It is built around the AERMOD dispersion model, and is driven by meteorology and local emissions constructed from proxy data.

To facilitate a fast setup for new urban areas, the project will publish the Retina codebase as an open-source project on the KNMI GitLab environment.

The design philosophy prioritizes local deployment, expecting users to download the open-source code and run the Retina system within their own computational environments.

The project also plans to conduct a feasibility study on whether the Retina model and its air quality products can be provided as a cloud-based "Software as a Service" (SaaS) in the future.

However, it is important to note that the Lobelia.Air viewer software used for the interactive visual data viewer will not be part of the open-source package, as the intellectual property for that viewer belongs to Lobelia.

Yes, while the focus of the first phase was nitrogen dioxide (NO₂), the current project phase will include generating an ozone (O₃) product at street level derived from NO₂ levels and other proxies.

The project is also exploring machine learning approaches to estimate surface PM2.5 concentrations and assessing potential for PM10.

For the customized implementation in Bratislava, integrating street-level maps for PM10 and PM2.5 is listed as a possible system addition.

Yes, by prioritizing local deployment of the open-source code, users are granted maximum flexibility to adapt the system to local needs and integrate their own data streams when more accurate or relevant resources are available.

For instance, in the customized monitoring system planned for Bratislava, the baseline system can be tailored using local data such as traffic counts from municipal campaigns, low-cost sensor networks, or Palmes diffusion tube campaign measurements.

To support the open-source publication of Retina, the project will foster an active user community by maintaining a central portal.

This portal will offer resources including a user forum, comprehensive documentation, installation guides, and tutorials.

The project is also assessing potential support from the ESA Application Propagation Environments (APEx), which could offer an initial technical analysis, use of instantiation services for a project collaboration environment, and developer support packages.

The project proposal includes an "Optional Work Package" which can be activated at ESA's discretion to support the tailored implementation of an air quality monitoring system specifically for the Bratislava municipality.

The consortium established a quotation framework through this optional package to tailor the baseline systems using local data.

Additionally, Lobelia mentions in their background that they have successfully integrated the Lobelia.Air viewer for clients like the City of Madrid and AMB, demonstrating previous commissioned work.

While formal training classes are not mentioned, the project will provide resources to help new users and developers get started.

These resources include comprehensive documentation, manuals, tutorials, installation instructions, and an active user forum.

The open-source codebase will also feature unit tests and end-to-end tests to enhance the developer experience.