Fig. 3
Sample walking route taken by a student research assistant carrying an AirBeam sensor on July 12, 2018. A The sampling route is circumscribed by the black rectangle, and the locations of nearby EPA monitoring stations are labeled according to site ID. Close-ups of the route colored according to B timestamps, C temperature (°C), D relative humidity (%), and E PM2.5 (μg/m3) recorded by the sensor, as well as F PM2.5 (μg/m3) estimates derived from EPA measurements via inverse-distance-squared-weighted interpolation. G Comparison of sensor and EPA measurements recorded during the sampling frame. The black star indicates the location of the research lab in panels A-F