A miniature, low‐power scientific fluxgate magnetometer: A stepping‐stone to cube‐satellite constellation missions

Difficulty in making low noise magnetic measurements is a significant challenge to the use of cube-satellite (CubeSat) platforms for scientific constellation class missions to study the magnetosphere. Sufficient resolution is required to resolve three-dimensional spatiotemporal structures of the magnetic field variations accompanying both waves and current systems of the nonuniform plasmas controlling dynamic magnetosphere-ionosphere coupling. This paper describes the design, validation, and test of a flight-ready, miniature, low-mass, low-power, and low-magnetic noise boom-mounted fluxgate magnetometer for CubeSat applications. The miniature instrument achieves a magnetic noise floor of 150–200 pT/√Hz at 1 Hz, consumes 400 mW of power, has a mass of 121 g (sensor and boom), stows on the hull, and deploys on a 60 cm boom from a three-unit CubeSat reducing the noise from the onboard reaction wheel to less than 1.5 nT at the sensor. The instrument's capabilities will be demonstrated and validated in space in late 2016 following the launch of the University of Alberta Ex-Alta 1 CubeSat, part of the QB50 constellation mission. We illustrate the potential scientific returns and utility of using a CubeSats carrying such fluxgate magnetometers to constitute a magnetospheric constellation using example data from the low-Earth orbit European Space Agency Swarm mission. Swarm data reveal significant changes in the spatiotemporal characteristics of the magnetic fields in the coupled magnetosphere-ionosphere system, even when the spacecraft are separated by only approximately 10 s along track and approximately 1.4° in longitude.

[1]  Electdom Matandirotya,et al.  Evaluation of a commercial-off-the-shelf fluxgate magnetometer for cube sat space magnetometry , 2013 .

[2]  Michael C. Kelley,et al.  Distinguishing Alfvén waves from quasi‐static field structures associated with the discrete aurora: Sounding rocket and HILAT satellite measurements , 1990 .

[3]  I. J. Rae,et al.  The Upgraded CARISMA Magnetometer Array in the THEMIS Era , 2008 .

[4]  Harlan E. Spence,et al.  Space Technology 5 multi‐point measurements of near‐Earth magnetic fields: Initial results , 2008 .

[5]  L. B. N. Clausen,et al.  Swarm in situ observations of F region polar cap patches created by cusp precipitation , 2015, 1606.02658.

[6]  Kathryn McWilliams,et al.  Observation of polar cap patches and calculation of gradient drift instability growth times: A Swarm case study , 2014 .

[7]  F. Primdahl.  The fluxgate magnetometer , 1979 .

[8]  B. B. Narod,et al.  Ring-core fluxgate magnetometers for use as observatory variometers , 1990 .

[9]  Mario H. Acuna,et al.  Magnetic Field Experiment on the Freja Satellite , 1994 .

[10]  Guan Le,et al.  Magnetic field gradients from the ST‐5 constellation: Improving magnetic and thermal models of the lithosphere , 2007 .

[11]  F. Grassa,et al.  Total (fumarolic + diffuse soil) CO2 output from Furnas volcano , 2015, Earth, Planets and Space.

[12]  H. Lühr,et al.  Swarm An Earth Observation Mission investigating Geospace , 2008 .

[13]  W. P. Olson,et al.  Magnetospheric Magnetic Field Modeling. , 1979 .

[14]  T. Potemra,et al.  The amplitude distribution of field-aligned currents at northern high latitudes observed by TRIAD. Interim report , 1975 .

[15]  Nils Olsen,et al.  DTU candidate field models for IGRF-12 and the CHAOS-5 geomagnetic field model , 2015, Earth, Planets and Space.

[16]  Ian R. Mann,et al.  A radiation hardened digital fluxgate magnetometer for space applications , 2013 .

[17]  Brian J. Anderson,et al.  Sensing global Birkeland currents with iridium® engineering magnetometer data , 2000 .

[18]  Ian R. Mann,et al.  The CASSIOPE/e-POP Magnetic Field Instrument (MGF) , 2015 .

[19]  C. J. Pellerin,et al.  A Miniature Two-Axis Fluxgate Magnetometer , 1969 .

[20]  P. A. Robertson.  Microfabricated fluxgate sensors with low noise and wide bandwidth , 2000 .

[21]  Albrecht Rüdiger,et al.  Spectrum and spectral density estimation by the Discrete Fourier transform (DFT), including a comprehensive list of window functions and some new at-top windows , 2002 .

[22]  Per-Arne Lindqvist,et al.  Fine structure of field-aligned current sheets deduced from spacecraft and ground-based observations: Initial FREJA results , 1994 .

[23]  M. H. Acuna,et al.  The MAGSAT vector magnetometer: A precision fluxgate magnetometer for the measurement of the geomagnetic field , 1978 .

[24]  H. Spence,et al.  New measurements of total ionizing dose in the lunar environment , 2011 .

[25]  Eric Hand.  Thinking inside the box. , 2015, Science.

[26]  Pavel Ripka,et al.  AC-driven AMR and GMR magnetoresistors , 1999 .

[27]  J. K. Bekkeng,et al.  Design of a multi-needle Langmuir probe system , 2010 .

[28]  Hermann Lühr,et al.  Determining field-aligned currents with the Swarm constellation mission , 2013, Earth, Planets and Space.

[29]  John R Wygant,et al.  Alfvén waves and Poynting flux observed simultaneously by Polar and FAST in the plasma sheet boundary layer , 2005 .

[30]  Pavel Ripka,et al.  Advances in fluxgate sensors , 2003 .

[31]  Pavel Ripka,et al.  High frequency fluxgate sensor noise , 1994 .

[32]  J. G. Sample,et al.  Space magnetometer based on an anisotropic magnetoresistive hybrid sensor. , 2014, The Review of scientific instruments.

[33]  F. Primdahl,et al.  Temperature compensation of fluxgate magnetometers , 1970 .

[34]  M. D. Michelena.  Commercial Off-The-Shelf GMR Based Sensor on Board Optos Picosatellite , 2013 .

[35]  Eric Jon Lund,et al.  Pi1B pulsations as a possible driver of Alfvénic aurora at substorm onset , 2011 .

[36]  Hermann Lühr,et al.  An algorithm for estimating field-aligned currents from single spacecraft magnetic field measurements: a diagnostic tool applied to Freja satellite data , 1996, IEEE Trans. Geosci. Remote. Sens..

[37]  Harald U. Frey,et al.  The detailed spatial structure of field‐aligned currents comprising the substorm current wedge , 2013 .

[38]  Brian J. Anderson,et al.  Estimation of global field aligned currents using the iridium® System magnetometer data , 2001 .

[39]  B. B. Narod,et al.  The origin of noise and magnetic hysteresis in crystalline permalloy ring-core fluxgate sensors , 2014 .

[40]  Serhiy Belyayev,et al.  Miniaturized digital fluxgate magnetometer for small spacecraft applications , 2007 .

[41]  E. Cupido,et al.  Magnetoresistive magnetometer for space science applications , 2012 .

[42]  Thomas E. Moore,et al.  Magnetospheric Multiscale Overview and Science Objectives , 2016 .

[43]  Martin R. Lessard,et al.  Fast Auroral Imager (FAI) for the e-POP Mission , 2015 .

[44]  Shoji Kawahito,et al.  An integrated micro fluxgate magnetic sensor , 1996 .

[45]  Stefan Leitner,et al.  Design of the Magnetoresistive Magnetometer for ESA’s SOSMAG Project , 2015, IEEE Transactions on Magnetics.

[46]  H. G. James,et al.  CASSIOPE Enhanced Polar Outflow Probe (e-POP) Mission Overview , 2015 .