Assessing Air Pollution in Urban Environments: A Comprehensive Analysis Using Earth Observation and In Situ Measurements

Abstract

This master's thesis investigates the feasibility of using Earth Observation and low-cost environmental sensors in urban areas to complement existing government monitoring systems to provide a sharper picture of air quality, which is a growing concern for the health and well-being of urban dwellers. The work uses NO2 tropospheric column data from the Copernicus Sentinel-5P satellite, regulatory PM10 readings and self-constructed low-cost sensor systems measuring PM10, ambient temperature and relative humidity. The environmental monitors were developed with computer-aided design, 3D printed, and their performance evaluated. A network of static sensors and a mobile system were deployed to better cover the urban space in Wuerzburg, Germany, and detect spatiotemporal patterns. Each of the three layers has its own limitations with satellites facing temporal and spatial resolution issues and cloud cover interference, regulatory data providing site-specific measurements but only publishing hourly averages, and low-cost sensors being sensitive to elevated relative humidity and cold ambient temperatures. However, the work also shows that with appropriate data and procedures, calibration of low-cost sensors is possible and that all three levels can be intertwined to make a valuable contribution to research and understanding of urban space and its pollution levels.