Dynamic gas sensor network for air pollution monitoring and its auto-calibration

The use of a dynamic gas sensor network is proposed for air pollution monitoring, and its auto-calibration is discussed to achieve the maintenance-free operation. Although the gas sensor outputs generally show drift over time, frequent recalibration of a number of sensors in the network is a laborious task. To solve this problem, instead of the static network proposed in the related works, we propose to realize a dynamic gas sensor network by, e.g., placing sensors on vehicles running on the streets or placing some of them at fixed points and the others on vehicles. Since each sensor in the dynamic network often meets other sensors, calibration of that specific sensor can be performed by comparing the sensor outputs in such occasions. The sensors in the whole network can thus be calibrated eventually. The simulation results are presented to show that adjusting the sensor outputs to the average values of the sensors sharing the same site improves the measurement accuracy of the sensor network.