5. Monitor Coverage Area and Representativeness

Spatial Representativeness

There is no universally defined distance covered by a single air quality monitor, as representativeness depends on local emission sources, meteorological conditions, topography, and urban morphology.

• General guideline — A monitor at a typical background location can provide data representative of approximately a 5 km radius.
• Near-source monitors — Monitors near major roads or industrial facilities represent more localised conditions (< 500 metres).
• Temporal factors — Rush-hour traffic can alter the spatial extent of a monitor's representativeness.

Network Density Requirements

AirQo Recommendation	At least one monitor per 10,000 people for high-resolution monitoring
City-Wide Patterns	Minimum 10–15 monitors recommended
Neighbourhood Studies	Higher density may be required
Strategic Placement	Background, traffic, and residential sites are as important as total number