Within the team at the Haagse Hoogeschool, Sam Aerts is a connecting link: “I worked at Ghent University until the end of 2022 and then transferred to the Haagse Hogeschool, to the Smart Sensor Systems lectorate. Back then in Ghent we were already working on 5G measurements and building sensors to perform long-term measurements. Here in Delft, TU Delft and Haagse Hogeschool were also working on their own sensors. It seemed ideal to compare our work. If we put all our measuring instruments together, will we see the same results? Or will there be differences? And can we explain those differences? What environmental factors affect our measurements?”
Uncertainties
Measuring electromagnetic fields is a very delicate matter. The sensors’ location is critical to the accuracy of the measurements. Sam explains: “We always deal with measurement uncertainties, because of varying signals in time and in space. That’s why we initially lined up five sensors adjacent to each other on a table and compared those values. Then we shifted them, to determine the influence of positioning. We also brought along a spectrum analyzer to perform very precise measurements. Sometimes the measurements turned out to be very divergent, because the sensors didn’t function as well as expected. That’s part of scientific research. Experimenting, making assumptions based on the results, verifying them through additional testing, and finally drawing conclusions.”
Some of the sensors that were tested at that time have now been installed at The Green Village, near Do IoT Fieldlab’s 5G installation. TU Delft colleagues Joep van der Weijden and Marijn Leeuwenberg were involved in setting up this research from the very start. After an initial inventory on the test specifications, supplies and possible risks, they drew up an agreement together. Joep: “The Green Village is a low-regulation environment. You don’t have to obtain all kinds of permits if you want to perform research. Beforehand, we want to define who is responsible for which equipment, when it is installed on our premises. We also had to determine together how and where to store the data. Together with our partner Surf, we created a configuration in which the EMV-sensors send a data package across the internet every 5 seconds. Data collection and analysis is up to the researcher. At The Green Village we want to facilitate in the best possible way. While researching partners can easily access the data themselves, they can also make use of our dashboard. Whichever is more convenient.”