MINTS: A Modular Integrated Network of Traffic Sensors for Collection and Visualization of Pollution Data

Sammanfattning

Traditional monitoring systems for urban pollution tend to be expensive, few in number, and often mounted on rooftops, farther from the directly affected areas on the ground. This thesis examines the viability of a denser, ground-level network to avoid these flaws. The study uses LoRa radio technology to design and build a node-gateway network for use in the urban environment of Uppsala, Sweden. The two objectives of the research are to evaluate the relationship between ground-level and rooftop-level particulate matter (PM) measurements and to assess the extent to which ground-level LoRa devices can maintain range and connectivity in a dense urban environment. LoRa radio performance is measured by calculating metrics such as packet loss rate between two LoRa nodes in several urban environments, using different LoRa parameters. The relationship between ground- and rooftop-level measurements is examined at two locations using our nodes to simultaneously measure PM1 and PM2.5 concentrations near the ground and at the rooftop. It was found that LoRa technology can sustain stable connections between ground-level devices in an urban environment at medium-to-long ranges. The radios generally do not require line of sight, except under high levels of occlusion at long ranges. These findings show the potential of LoRa for effective use within a node-gateway system in an urban setting. The PM measurements showed elevated ground-level readings compared to rooftop readings, highlighting the importance of regulatory measuring stations being positioned at ground level for accurate results. This study contributes to the field by further exploring the use of LoRa technology in urban environments and highlighting the importance of ground-level air pollutant measurements. The complete source code for the node and gateway firmware, as well as the frontend and database software, can be found on GitHub.