Fig. 2
Summary of sensor field trials and comparison with EPA estimates. A Regions sampled by AirBeam sensors are indicated in red and circumscribed by the black rectangle, and Philadelphia county is outlined in grey. The locations of EPA monitoring stations are denoted by pale yellow diamonds, with the three closest stations labeled by their site ID’s. Surveyed streets shaded according to B the number of sensor PM2.5 measurements taken on each block, C block-level mean PM2.5 measured by sensors, D block-level mean PM2.5 estimated from time-matched EPA measurements, and E difference between PM2.5 measured by sensors vs. estimated using EPA measurements. The black star indicates the location of the research lab in panels B-E