Brussels / 3 & 4 February 2024


MiniMill: a miniature Field Mill Electrometer for airborne platforms

A robust, miniaturized and open-source version of an electrostatic fieldmeter sensor, the MiniMill, is presented. The sensor is designed for a fast-response detection of the atmospheric electric field strength, an intrinsic parameter of the Global Electric Circuit (GEC) that electrically links the Earth’s surface to the upper levels of the atmosphere. Such a field varies greatly with the various weather conditions due to the re-distribution of charged or uncharged aerosols and terrestrial radioactive particles. Field mill electrometers have been consecutively used for ground-based measurements of such fields under diverse conditions, but sparse iterations of the sensor exist that can be tethered to airborne measurement platforms. The lightweight, disposable and easily reproducible design of the MiniMill allows the use on agile platforms, such as weather balloons, UAVs or even campaign aircrafts, and achieves a measurement accuracy of a few V m-1 on DC fields. MiniMill performance has been tested in vertical profiling measurements during scientific experiments in 2019 and 2022, where sensor “constellations” were launched on-board meteorological radiosondes under both fair weather conditions and large tropospheric dust events originating from the Sahara Desert. The sensor’s response exhibits a clear influence to the vertical large scale electric field when charged dust particles are present in the atmospheric circulation, which is a significant research achievement. Also, we would like to share the inherent challenges of such a sensor (or, you know, lots of sensors) implemented entirely within the academic and research community. Let's brainstorm ways to make these sensors even more awesome together!


Photo of Lilly Daskalopoulou Lilly Daskalopoulou