FILTER (VALAIR)
FILTER (Framework for Improving Low-cost Technology Effectiveness and Reliability) improves the quality of citizen-generated air quality data. With the rise of low-cost sensors, such as those from Sensor.Community and PurpleAirenable communities to measure air locally, but the data often requires correction to be reliable for research and policy purposes.
FILTER applies advanced quality checks and correction methods to PM2.5 data, detecting errors, flagging uncertainty, and producing harmonized datasets that are easier to trust and use. Already tested on over 500 million measurements, it has improved data accuracy by more than 50%.
By bridging grassroots monitoring with institutional standards, FILTER makes citizen-collected data more usable at every level of governance and directly supports the goals of the European Air Quality Directive (2024).
Explore the tool
GitHub (Code & Resources): https://github.com/CitiObs/ValAir
Research Article: https://www.sciencedirect.com/science/article/pii/S030147972501076X
FILTER Repository:
