A low-cost holographic sensor for urban aerosol characterization

Urban environments, with their diverse landscapes and sociodemographic makeups, pose challenges for environmental and atmospheric measurement, especially of coarse mode aerosols, which includes particles critical to climate, air quality, human health, and agriculture. Our project addresses this gap through the development of the Passive Aerosol Imager (PAI), employing digital inline holography (DIH). DIH, in contrast to traditional light scattering methods, provides direct images of all particles in the imaging volume, enabling precise size and shape analysis. Phase I focused on designing, assembling, and testing a breadboard based PAI. We demonstrated the techniqueĺs potential for urban aerosol characterization and network deployment. Building on this, Phase II aims to refine and test three prototype sensors in urban settings. We will improve data processing accuracy and efficiency, develop a cloud-based data storage and visualization platform, and validate the instrument in real-world settings. The successful deployment of the PAI promises substantial public benefits in healthcare, agriculture, urban planning, and environmental monitoring, improving understanding and management of air quality and its broad impacts.