Simplifying urban microclimate studies: A low-cost mobile temperature monitoring system with automatic correction

Urban thermal environments exhibit significant spatial heterogeneity. Acquiring high-resolution temperature data is crucial for understanding urban microclimates. Mobile measurements have been widely utilized to collect temperature data for urban climate research. However, existing instruments for mobile observations typically comprise various sensors, data acquisition devices, and locators, resulting in challenges, including high costs, bulkiness, complex assembly, and intricate data processing. We developed a low-cost, portable mobile monitoring system (MMS) for urban air temperature to address these issues, utilizing the open-source Arduino UNO R3 microcontroller board. The MMS comprises a handheld meter for temperature data collection, a smartphone application, and desktop software. The performance of the MMS was compared with two industrial-grade instruments. Comparative experiments demonstrated that the MMS met the requirements for mobile temperature measurements in terms of accuracy, response time, and the effectiveness of its radiation shield. In addition to its low cost, portability, and user-friendly design, the MMS features automatic temporal correction and Inverse Distance Weighting spatial interpolation for air temperature data. Moreover, multiple MMS units can operate in a network, significantly enhancing spatial coverage and sampling density. Field measurements were conducted on a campus to evaluate the MMS, and the results were compared with data from a network of 30 fixed stations. The MMS simplifies temperature data acquisition, reduces data processing complexity, and increases sampling density. These advantages make the MMS highly applicable for mobile observations of urban temperature. We anticipate that the MMS will serve as a valuable tool for monitoring urban thermal environments.