Van Allen Probes instrument calibration results of the for ECT-HOPE and
RBSPICE energetic particle detectors
Abstract
Understanding the dynamical behavior of plasma and energetic particles
in Earth’s inner magnetosphere requires carefully designed and
calibrated instrumentation. The Van Allen Probes Mission included two
instruments capable of measuring the proton distribution function
in-situ. The Energetic Particle Composition and Thermal Plasma Suite
(ECT) – Helium Oxygen, Proton, and Electron (HOPE) spectrometer (Spence
et al., 2013; Funsten et al., 2013) used a top-hat detector designed to
measure protons from the SC potential through 50 KeV in logarithmic
energy steps. The Radiation Belt Storm Probes Ion Composition Detector
(RBSPICE) instrument (Mitchell, 2013) used a time of flight and SSD
detector design to measure protons from approximately 7 KeV through 650
KeV in logarithmic energy steps. Using the overlap of energy channels
between the two instruments, the two instrument teams have worked
diligently during the final Phase F of the mission to calibrate the
observations so that a continuous distribution function can be resolved
on nearly a spin-by-spin basis. During the life of these two instruments
calibration changes have been required both on-board the spacecraft as
well as within the final production datasets. Manweiler (2018) provided
an early report on the intercalibration factors between HOPE and RBSPICE
with a nominal factor of two difference between the proton data sets in
the energy range between 7 and 50 KeV. With the final production of each
of these data sets occurring in Fall 2021, both teams have been worked
together to provide for an understanding of the required
intercalibration factors to be used so that a full distribution function
is available on a spin-by-spin basis. In this poster we report on the
final efforts to provide this calibrated set of data products between
the two instruments. Details of the intercalibration calculations are
presented as well as year by year L by MLT maps of the factors required
to match both datasets. Finally, we report on a supplementary data set
that is to be made available which contains the spin-by-spin factors
required to match the ECT/HOPE and RBSPICE/TOFxPH proton datasets.
Funsten, H.O., et al. Space Sci Rev 179, 2013 Manweiler, J. W., et al.,
2018 GEM Summer Workshop. Mitchell, D.G., et al., Space Sci. Rev., 179,
2013 Spence, H.E., et al. Space Sci Rev 179, 2013