Ten years of operation of Swarm's absolute magnetometers, lessons learnt and prospect for the NanoMagSat nanosatellite constellation project

ESA Swarm satellites carry a magnetometry payload consisting of an absolute scalar magnetometer (ASM), a relative flux gate vector magnetometer (VFM), and a set of star trackers (STR). The primary role of the ASM is to provide precise 1 Hz absolute field intensity measurements, while the VFM and STR provide the additional data needed to accurately reconstruct the vector field. This magnetometry payload has provided a remarkable set of nominal vector data, which has extensively been used for multiple investigations, as illustrated by the many results presented in this session. Each ASM instrument, however, can also produce its own self-calibrated 1 Hz experimental vector data, or, when requested, 250 Hz scalar burst mode. Self-calibrated 1 Hz experimental vector data have routinely been produced ever since launch, and substantial amount of scalar burst mode sessions have now also been run, mostly since 2019, when the decision was made to run such sessions one week per month on both the Alpha and Bravo satellites. In this presentation, we will illustrate the added value both these datasets brought to the Swarm mission, with the self-calibrated 1 Hz experimental vector data contributing to improvement and validation of the nominal dataset, and the burst mode data bringing new science opportunities. We will also discuss the lessons learnt from operating the ASM instruments on Swarm and how these led to the development of an appropriate miniaturized magnetometry payload for the NanoMagSat nanosatellite constellation. This constellation project is currently under development in the context of the ESA Scout program, and aims at a launch in the near future for complementing and enhancing the science return of the Swarm mission.