  As air pollution is becoming the largest environmental health risk, the
monitoring of air quality has drawn much attention in both theoretical studies
and practical implementations. In this article, we present a real-time,
fine-grained and power-efficient air quality monitoring system based on aerial
and ground sensing. The architecture of this system consists of four layers:
the sensing layer to collect data, the transmission layer to enable
bidirectional communications, the processing layer to analyze and process the
data, and the presentation layer to provide graphic interface for users. Three
major techniques are investigated in our implementation, given by the data
processing, the deployment strategy and the power control. For data processing,
spacial fitting and short-term prediction are performed to eliminate the
influences of the incomplete measurement and the latency of data uploading. The
deployment strategies of ground sensing and aerial sensing are investigated to
improve the quality of the collected data. The power control is further
considered to balance between power consumption and data accuracy. Our
implementation has been deployed in Peking University and Xidian University
since February 2018, and has collected about 100 thousand effective data
samples by June 2018.
