The PICASE suite for radiation space weather monitoring at LEO: initial concept

The study of the space radiation environment surrounding Earth is a fundamental aspect of space weather research, as high-energy particles pose a significant threat to the electronics on every single launched satellite. The gap between Van Allen's outer and inner electron radiation belts is filled by the high-energy electrons shifted radially inward from the outer belt due to a variety of physical mechanisms. They comprise geomagnetic storms, interactions between sub-relativistic particles, and electromagnetic emissions of both natural and artificial origin.

Recent advancements in this field have led to the discovery of a third persistent electron radiation belt at L ~ 1.6 as identified by the STEP-F instrument (Dudnik et al., 2022). Furthermore, empirical evidence suggests that the medium-scaled variations of ionospheric total electron content (TEC) at the middle latitudes can be associated with sporadic microbursts of high-energy electrons below Van Allen radiation belts and within the gap separating inner and outer belts. These findings underscore the necessity of continuous and precise monitoring of the near-Earth radiation environment.

In this study, we introduce the initial concept of the Particle Instrument for Combined Analysis of Space Environment (PICASE) will be designed in a frame of ESA’s Space Weather Nanosatellites System (enhancement study) initiative. The suite intends for uninterrupted monitoring of the high-energy electron and proton fluxes in low Earth orbit (LEO). The instrument is being designed to achieve high energy and time resolution, enabling detailed comparative analyses of charged particle dynamic energy spectra within the Van Allen radiation belts, and in microbursts occurring outside the belts and the South Atlantic Anomaly.

The methodological approach of PICASE involves the determination of particle sort, precise determination of individual particle energies, separately for electrons and protons, and accumulation of particle counts within a predefined aperture. To generate dynamically changed radiation maps across various energy at satellite altitudes we expect continuous, full-day measurements. To distinguish trapped and precipitating particles, and those induced by human activities and ionospheric storms from each other the instrument will incorporate three detector heads equipped with large-area active sensors. Expected technical characteristics and structural block scheme of PICASE are presented too.

This work is supported by the “Long-term program of support of the Ukrainian research teams at the Polish Academy of Sciences carried out in collaboration with the U.S. National Academy of Sciences with the financial support of external partners”.

This research was carried out in collaboration with the European Space Agency (ESA), under contract 4000146628/24/D/SR.

Reference.

O.V. Dudnik, J. Sylwester, M. Kowaliński, P. Podgórski, K. J.H. Phillips. Detection of the third innermost radiation belt on LEO CORONAS-Photon satellite around 2009 solar minimum. Advances in Space Research, 2022. Vol. 70, pp.1441–1452.