The SARWS project
The SARWS European Project is a 3-years (2018-2021) telecommunication project with a budget of 11 M€ (funded by the Celtic-Next/EUREKA) and constituted of 26 partners from 7 countries: Spain, Turkey, South Korea, Portugal, Romania, Belgium and France. This collaborative project aims to exploit Cooperative Intelligent Transport Systems (C-ITS)[1] to provide real-time location-aware meteorological and air quality services composed from multi-modal data. In other words, the objective is to develop innovative ways to collect weather and pollution data from mobile sensors.
Within the project, eLichens is involved in the design of mobile air quality microsensors and fine scale air quality modelling. eLichens has recently completed the first part of this mission by designing a mobile air quality device and conducting tests in real conditions.
Why developing a mobile air quality microsensor?
Mobile air quality monitors enable measurements across large urban areas easily. Moreover, they are an asset to identify pollution spots which are not covered by fixed sensors networks. They could represent an effective complement to fixed microsensors in the future.
What are the existing mobile solutions to track urban pollution?
Several mobile sensing technologies already exist for ambient monitoring, including:
· Laboratory vehicles: some are considered reference stations, and most are equipped with scientific instruments. They are very costly.
· Portable sensors: they follow their owner everywhere, but the quality of the measurements is not optimal in most cases.
· Drone sensors are very useful to monitor industrial sites or private areas. However, local regulations may not allow them to operate within cities.
eLichens’ contribution: a mobile air quality microsensor
Pictured: the prototype dimensions. The mobile microsensor is designed to be fixed on a vehicle
To design a mobile microsensor, eLichens transformed its existing product eLos which is a fixed solar-powered air quality monitoring station. eLos collects and communicates hourly concentrations of pollutants such as particulate matter (PM1, PM2.5, PM10), nitrogen dioxide (NO2), ozone (O3) as well as climate parameters such as temperature, pressure, humidity. Cloud-based recalibration algorithms ensure a high stability of its measurements over years.
First tests on the mobile device were conducted in Grenoble, France, in October 2020. The mobile sensor was fixed on top of a car.
The prototype measures ambient air quality every 10 seconds (one measurement every 250 meters at a speed of 70km/h). It is waterproof and includes a system to overcome the main challenge of mobile air quality sensing: variability of air flow. Its casing offers similar air flow conditions whatever the speed of the vehicle is, from 0 to 70 km/h. The station is now operational thanks to an embedded 3G data transmitter and a GPS module. eLichens’ web application has also been extended to allow real-time visualization of the measurements coming from the mobile station.
Figure 1: Evolution of PM10 concentration in relation to vehicle speed. Measurements were carried out during a measurement campaign in Grenoble on August, 28, 2020 from 11 to 11:30AM
Next steps
The next project steps will be the validation of the recalibration algorithm and the development of a method to assimilate these measurements in eLichens’ air quality prediction model. The real-time mapping service based on mobile data is planned for late 2021-early 2022 with a live demonstration.
[1] Intelligent Transport System (ITS) are digital technologies applied in the field of road transport to, mainly, improve the efficiency and safety of transport like traffic management or mobility. Connected devices are located, for example, in vehicles or at roadside infrastructure. Cooperative ITS focuses on the communication between those systems, i.e. vehicles will interact directly with each other and with the road infrastructure to allow an increased sharing of information and thus the creation of numerous services and safer and more efficient mobility.
