The AQSN Network

The AQSN ("Air Quality Sensor Nodes") network measures atmospheric concentrations of NO₂, NO, O₃, CO, and particulate matter around Munich's Maxvorstadt neighborhood. The resulting data is used to evaluate the air quality and can support the city in making effective decisions.

The network consists of 50 solar-powered sensor nodes. The sensor nodes are autonomous and measure around the clock. You can see their status in the dashboard in real-time.

The AQSN network is a "low-cost" sensor network, which means that the hardware is relatively inexpensive. This way we can deploy sensor nodes in a very high spatial resolution. The downside is that measurements are less sensitive and experience drift over time. We account for this by calibrating the sensor nodes in regular intervals with a mobile reference instrument and applying machine learning algorithms in our processing pipeline.

Sensor nodes take new measurements every 10 minutes. The sensor nodes communicate with a server, to which they transmit their measurements and through which they can be configured remotely. The server is written in Python and deployed on Google Cloud. The data store behind the server is PostgreSQL with the TimescaleDB extension.

The AQSN network is being developed by the Associate Professorship of Environmental Sensing and Modeling at the Technical University of Munich.

Grant information

• Funded by the Bavarian State Ministry of the Environment and Consumer Protection
• TLK01U-75487: "Engmaschiges NO₂ Sensornetzwerk in München"
• Timeframe: July 2023 - July 2024