Fig. 2
From: QUANT: a long-term multi-city commercial air sensor dataset for performance evaluation

Panels (a,b) show the Manchester Air Quality Supersite (MAQS) site, characterized by its range of atmospheric monitoring instruments in an urban environment. Panel (b) provides a view of the rooftop setup with multiple sampling devices. Panels (c,d) present the London Air Quality Supersite (LAQS). Panel (c) shows a general perspective of the site, while panel (d) provides a close-up of the measurement devices installed on the roof. Finally, panel (e) illustrates the York air quality monitoring site (YoFi), located next to a road, with a single green container housing the sensor systems on the roof, and the reference instruments inside.