Why take measurements ?
For the public, measuring ambient radioactivity makes it possible to participate in territorial monitoring in addition to existing associative or institutional monitoring networks. It also allows participation in scientific projects such as those on the impact of solar flares on board aircraft (in-flight measurements) or certain electrical phenomena in storms (see Terrestrial Gamma Flash, TGF) (in-flight and ground measurements).
This approach also has a pedagogical dimension. Indeed, making measurements in your environment allows you to better understand the phenomenon of radioactivity, to better understand the levels of exposure and possible associated risks, and finally, to form your own opinion and, if necessary, to draw lessons from it in your daily life.
One of the lessons learned from the Fukushima Daiichi accident is that the lack of knowledge and understanding of events and their consequences in a crisis situation is extremely stressful for the people directly concerned but also for remote witnesses. Thus, the citizens, directly affected or not, who collect the data characterizing the places and share them, contribute to usefully informing the population to deal with such situations.
Within the OpenRadiation project, this pedagogical dimension was taken into account from the beginning with the provision of a "kit" dosimeter (i.e. to be assembled yourself) and an intuitive and didactic smartphone application (measurement reliability indicator, possibility to enter environmental parameters...). In addition, the site offers the opportunity to have exchanges and discussions around specific measures or advice on good practices for carrying out measurements.
Why take measurements in flight?
While exposure to the galactic component of cosmic radiation on board aircraft is well known and can be modelled, this is not the case for exposure related to solar flares with protons sufficiently energetic to cross the magnetosphere. Scientists studying these eruptions have limited observational data, due to operational difficulties in setting up measurement networks at flight altitudes. These data are necessary to validate and improve the tools and models used to calculate the doses received (see the SiGLE model developed by Paris Observatory and used in the SIEVERTPN tool for calculating doses on board aircraft, www.sievert-system.org).
Since solar flares with an effect on aircraft flight levels are rare, last no more than a few hours and are difficult to predict, it is necessary to have the widest possible permanent coverage in terms of measurement equipment.
The Cosmic On Air project (cosmic-on-air.org) aims to stimulate the measurement of cosmic radiation on board aircraft by the general public using the tools already available in OpenRadiation. This citizen measurement project makes it possible to extend cosmic radiation measurements to different latitudes or periods and thus increase the chances of detecting different cosmic and atmospheric phenomena (significant solar flares, gamma flash in storms, quantifying the attenuation of the dose due to Forbush decreases) or to identify other still unknown phenomena. The open data collected in this way can be more widely used by the scientific community to better understand these phenomena and their impacts.
The analysis of the collected data will also improve knowledge of detector performance, refine their calibration and ultimately provide a better dose estimate.