STAFF instrument calibration, sensitivity, and performance evolutions during the cluster mission
File(s)
Accepted version
Author(s)
Type
Journal Article
Abstract
The Spatio-Temporal Analysis of Field Fluctuations(STAFF) instruments onboard the Cluster satellites were designed to measure magnetic fluctuations in the 0.2–12 Hz and 0.2–180 Hz frequency ranges from the Search-Coil Magnetometer (SCM), as well as electromagnetic
spectra from the Spectrum Analyzer (SA) in the 8–4000 Hz range. They provided a considerable
amount of data throughout the 24-year mission. The production and calibration of these datasets were detailed in Robert et al. (2014), which demonstrated its excellent quality and good agreement with the FluxGate Magnetometer (FGM) measurements over their common
frequency range. The Cluster's 24 years of operation, which far exceed the nominal two-year mission, represent the longest flight of search coil magnetometers and offer a unique opportunity to evaluate their performance over such a long period, as well as to compare the results of four initially identical instruments. The present work, based on data now archived at the Cluster Scientific Archive (CSA), examines the evolution of these products after the first 11 years in space, and until the end of the Cluster operations in September 2024. The quality of the measurements, calibration, sensitivities, and their agreement between spacecraft proved to be excellent and remained stable throughout the mission. Comparison of spectra derived from the calibrated waveforms of STAFF (CWF) and FGM shows a very good agreement until the end of operations, a further proof of the high quality of their respective calibrations.
spectra from the Spectrum Analyzer (SA) in the 8–4000 Hz range. They provided a considerable
amount of data throughout the 24-year mission. The production and calibration of these datasets were detailed in Robert et al. (2014), which demonstrated its excellent quality and good agreement with the FluxGate Magnetometer (FGM) measurements over their common
frequency range. The Cluster's 24 years of operation, which far exceed the nominal two-year mission, represent the longest flight of search coil magnetometers and offer a unique opportunity to evaluate their performance over such a long period, as well as to compare the results of four initially identical instruments. The present work, based on data now archived at the Cluster Scientific Archive (CSA), examines the evolution of these products after the first 11 years in space, and until the end of the Cluster operations in September 2024. The quality of the measurements, calibration, sensitivities, and their agreement between spacecraft proved to be excellent and remained stable throughout the mission. Comparison of spectra derived from the calibrated waveforms of STAFF (CWF) and FGM shows a very good agreement until the end of operations, a further proof of the high quality of their respective calibrations.
Date Issued
2026-06-01
Date Acceptance
2026-06-05
Citation
Journal of Geophysical Research: Space Physics, 2026, 131 (6)
ISSN
2169-9380
Publisher
American Geophysical Union (AGU)
Journal / Book Title
Journal of Geophysical Research: Space Physics
Volume
131
Issue
6
Copyright Statement
Copyright © 2026. American Geophysical Union. All Rights Reserved. This is the author’s accepted manuscript made available under a CC-BY licence in accordance with Imperial’s Research Publications Open Access policy (www.imperial.ac.uk/oa-policy)
License URL
Publication Status
Published
Article Number
e2026JA035072
Date Publish Online
2026-06-22