Ground Magnetometer
Array Planning:
Report of a Workshop
Compiled and edited byMark Engebretson, Augsburg College
Eftyhia Zesta, NASA Goddard Space Flight Center
January 17, 2017

TABLE OF CONTENTS
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2. Scientific Value of Ground Magnetometer Arrays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3. Current Organizational and Funding / Financial Challenges . . . . . . . . . . . . . . . . . . . . . . . . 9
4. Issues Addressed at the Workshop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5. Recommendations of the Geospace Portfolio Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
6. Examples of Governance and Organization in other Scientific Facilities . . . . . . . . . . . . . . . 19
7. Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
8. Higher Level Data Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
9. Class 2 Facility Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
11. U.S. Ground-Based Magnetometer Arrays and Programs . . . . . . . . . . . . . . . . . . . . . . . . . . 32
12. Workshop Participants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
13. List of Ground Magnetometer Array Web Sites Serving Magnetometer Data . . . . . . . . . . . . . 34
14. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

EXECUTIVE SUMMARY

Proceedings of the Workshop on Ground Magnetometer Array Planning: May 5-6, 2016
Dr. Mark J. Engebretson
Professor of Physics, Retired
Augsburg College, Minneapolis, MN
Dr. Eftyhia Zesta
Chief of the Geospace Physics Laboratory,
Heliospheric Physics Division
NASA/Goddard Space Flight Center, Greenbelt, MD
Publication supported by National Science Foundation grant AGS-1639587© 2017
Augsburg College
2211 Riverside Avenue
Minneapolis, MN 55454

Ground magnetometer arrays are one of the oldest
types of observational tools used to study Earth’s
space environment, and they continue to provide
essential data for a variety of studies of Earth’s
ionosphere and magnetosphere. These arrays haveincreasingly been eclipsed in visibility and fundingat the National Science Foundation by newer, larger,
and more expensive research instruments, but still
operate using the organizational and funding
structures first put in place several decades ago. In
particular, magnetometer array teams continue tocompete for funding in NSF’s base program against
data analysis proposals (which have no equipment
or maintenance costs). For many such arrays
this has led to lapses in array funding, and slow
progress in upgrading instrumentation, achieving
near-real-time data transmission from remote sites
to the host institutions, and providing the wider
space science community with rapid access to datain common formats.

Numerous scientific advisory panels since the early
1990s have stressed the continuing importance ofground magnetometer arrays, and most recently
two have suggested new organizational structures
as well. The 2013 Solar and Space Physics Decadal
Survey suggested placing ground magnetometer
arrays in the context of a new model of groundbased observations, Distributed Arrays of Small
Instruments (DASI). The 2016 Portfolio Reviewof the Geospace Section of the Division of
Atmospheric and Geospace Science of the National
Science Foundation [NSF, 2016] considered how
best to operate and support these arrays, andrecommended that they be moved toward fundingas Geospace Science Facilities, an organizationaland funding category first developed for large,
single-location ionospheric radars but now used forseveral other NSF-AGS research efforts in spacescience as well.
Ground Magnetometer Array Planning iv

Shortly after the Portfolio Review was firstdelivered to NSF, NSF-AGS personnel andmembers of the ground-based magnetometer
community began making plans for a workshop
to discuss the response of the community to theserecommendations, and suggest steps leading to
improved array operation and scientific use. This
report provides the background for this workshop,
held May 5-6, 2016, describes the current stateof U.S.-funded ground magnetometer arrays,
gives examples of other collaborative groundbased scientific efforts, and presents findings andrecommendations developed during the workshop
and in subsequent communications among
participants.
The recommendations presented below are grouped
into three phases, outlining a systematic transition
from the largely independent operations of current
NSF-funded ground magnetometer array teams
to what is hoped will be a more efficient andscientifically productive collaborative effort. These
recommendations include a) Initial steps that canbe accomplished by the community immediately
or within a few months, b) Near-term steps to be
implemented by the community and NSF within
1 to 3 years, and c) Longer-term steps to be
implemented by the community and NSF within
5-10 years, the time frame by which the Portfolio
Review’s suggested reprioritization of funding for
NSF-AGS Facilities will be completed.
A key characteristic of these recommendations is
a stepwise transition from the current model of
independently funded array teams, each of which
deploy, operate, and maintain magnetometers
at remote sites, retrieve their data, process andreformat it as necessary, distribute it via individual
web sites and/or one or more centralized datarepositories, and perform scientific analyses andv Ground Magnetometer Array Planning

prepare higher-level data products as appropriate,
to a much more coordinated model of operations
funding, separate from funding for scientificanalysis.
In the near term, this involves a) establishing a
Ground Magnetometer Array Advisory Board offrom 4 to 6 members, b) developing and funding
one (or a small number of regional) Ground
Magnetometer Diagnostics and Response Units
that will monitor and support operations anddata transmission of all U.S.-funded groundmagnetometer arrays, c) providing sufficient support
to SuperMAG, a current Class 2 Facility within
NSF-AGS, to enable it to ingest, store, and serve
the full set of data from all U.S.-funded fluxgate
and induction coil magnetometers at their original
sampling rates, d) developing, in conjunction withthe emerging DASI community, global higher levelproducts to support scientific efforts using otherground-based instrumentation, spacecraft missions,and computer simulations, and e) developing
improved ground magnetometer array systems(sensors, data recording and storage computers, anddata transmission technologies and protocols).
In the longer term, and building on the nearterm steps above, we recommend developing
and funding one or more multi-institution Class
2 Facilities to operate, monitor, and maintain all
NSF-funded ground-based magnetometer arrays.
It is expected that operation of this Facility will
result in more consistent up-time of arrays andindividual stations and possibly in cost savings aswell. Also recommended are to install improved,
identical magnetometer sensor, recording, anddata transmission systems to the extent that thisis financially and logistically feasible, following
other cited NSF-funded examples such as IRIS,UNAVCO, and SuperDARN.

CHAPTER 1

INTRODUCTION
Since the beginning of the space age, increasingly
sophisticated efforts have been made to explore
and understand Earth’s space environment. The
National Research Council’s report on the National
Geomagnetic Initiative Workshop, held March 16-20,
1992 [National Geomagnetic Initiative, 1993], provided
a useful summary of the scientific importance ofstudies of Earth’s magnetic field for increasing ourunderstanding of physical processes both in the
Earth’s interior and in the Earth’s surrounding spaceenvironment. Because Earth’s magnetic field reaches
out into space, and electrically charged particles aswell as several kinds of plasma waves are guided along
magnetic field lines, arrays of ground magnetometers
have long been a valued means of remotely monitoringprocesses in the ionosphere and throughout themagnetosphere.
The Topical Working Group Report on the
Magnetosphere, Ionosphere, and Atmosphere in the
National Geomagnetic Initiative [1993] highlighted
both the impact of what is now called “space weather”
on both terrestrial and space-based technologicaland natural systems, and outlined operational
considerations for continued and future deployment ofground-based magnetometer arrays.
Many of this report’s recommendations for
improvements in the use of ground magnetometers
for the study of the magnetosphere, ionosphere, andatmosphere are already being implemented by someindividual research groups, but the style of research isonly gradually changing from performing large studies
with a single station or a handful of localized stations

to trying to look at simultaneous data from stations at
multiple latitudes and local times. However, the valueof near-real time data distribution and access is clear,as is the need for extensive collaboration to standardize
data formats and to distribute and display ground arraydata. The digitization of all magnetometer data andthe advent of the internet makes this possible.
Since that report was issued, several efforts to integrate
all ground magnetometer data have emerged.
By 1993 the INTERMAGNET (International RealTime Magnetic Observatory Network) program, avoluntary association of geophysical institutes fromaround the world formed in the late 1980s (Loveand Chulliat, 2013), had already collected digital
data from 25 ground-based magnetic observatories(which measure both the absolute field and its vector
components with high accuracy) at four Geomagnetic
Information nodes, but the cadence of this data was atbest 1 minute per sample; it now involves 129 stations,and many of these (63) have already upgraded to
1-second sampling. Of those, 46 stations report data
to the INTERMAGNET site in near real-time.
ULTIMA (the Ultra-Large Terrestrial International
Magnetometer Array), a worldwide consortium of space
physics-related magnetometer array programs foundedin 2006, acts as a means of international communication
between different programs, and has tried to foster
integrated support for large missions and global studies
that can address scientific questions that could not beanswered before. Nearly all of the ULTIMA arrays
instruments are so-called variometer arrays; theseGround Magnetometer Array Planning 1

Figure 2.
Global equivalentcurrents during
an auroral
substorm, from theSuperMAG web
site, superposed ona simultaneous
Polar VIS Earthcamera image.
Measured vectors
are shown in green
and derived global
equivalent currents
in black.

Figure 1.
Map of worldwide magnetometer sites and arrays as of Fall 2016: US fluxgates arrays (magenta); US induction
coil arrays (blue); and non-US (grey).
measure the vector field but not the absolute field anddo not adhere to the rigorous calibration standards
required for magnetic observatories [Love and Finn,
2017]. However, the disparate regulations and policies
of funding agencies in different countries, and the lack ofany funding resources to support the synthesizing of all of
this data and providing it in a simple, accessible manner,have prevented full realization of ULTIMA’s promise.
Nearly 300 ground-based magnetometers have been
installed in over 40 countries worldwide (Figure 1).
Of these, 256 are included in arrays that are part of
ULTIMA, and there are 132 U.S.-funded fluxgate andinduction coil systems (in the U.S. and 15 other countries).
As noted below, many of these, including several arraysin the continental U.S., have experienced inconsistent or
minimal funding, and some are no longer operational.
2 Ground Magnetometer Array Planning

A more recent program, SuperMAG, was funded
beginning in 2009 in order to integrate as much dataas possible to study the currents that flow in the Earthgeospace system. Whether these currents originate in the
Earth’s crust, the ionosphere, or in the magnetospherethey produce magnetic field perturbations that can bemeasured by ground-based magnetometers. With carethese currents can be monitored by magnetometers
distributed around the globe and their spatiotemporalcharacteristics can be determined.
SuperMAG ingests not only INTERMAGNET
data but data from many variometer arrays deployedspecifically for space physics studies. The SuperMAG
web site (http://supermag.jhuapl.edu/) has becomea very useful one-stop web access site for worldwide
ground-based magnetometer data (at 1-minute time

resolution), global indices, and several higher level
data products, such as the northern hemisphere mapof equivalent ionospheric currents shown in Figure 2.

data has continued to be stressed in scientific planningdocuments. The first three examples below are takenfrom a draft report by Love and Finn [2017]:

However, scientists outside the ground magnetometer
community still find it difficult to access data obtained
at higher sampling rates, which are essential for studiesof the many shorter-period magnetic perturbations andoscillations, because these data sets are in many cases
available to the scientific community only throughweb sites developed by individual arrays (often in
nonstandard data formats) or for some arrays throughthe THEMIS ground magnetometer online dataarchive (http://themis.ssl.berkeley.edu/data/themis/
thg/mirrors/mag/) and NASA’s CDAWEB facility(http://cdaweb.gsfc.nasa.gov/.

•

A 2009 NOAA observation requirements list
described ground magnetometer data from eachof the three regions of auroral, mid-latitude, andlow-latitude as “priority-1” and “mission critical”
for space-weather monitoring [NOAA, 2009].

•

A 2012 Statement of Guidance for Space
Weather Observations conducted by the World
Meteorological Organization (WMO) InterProgramme Coordination Team on Space
Weather (ICTSW) recognized the need forground-based magnetometers for a variety ofspace-weather applications, and recommended
that efforts be made to increase the availability

The scientific importance of ground magnetometer

Ground Magnetometer Array Planning 3

of ground-based magnetometer data with hightimeliness [WMO/ICTSW, 2012]•

A 2015 strategic plan commissioned by theCommittee on Space Research (COSPAR) of theInternational Council for Science (ICSU) and theInternational Living With a Star (ILWS) Steering
Committee called for an increase in the availabilityof ground-based data on the geomagnetic field with“high timeliness” [Schrijver et al., 2015, p. 2770].

•

The National Science and Technology Council/ Office of Science and Technology Policy in2015 published two documents, the National
Space Weather Strategy, [2015] and National Space
Weather Action Plan, [2015], that also stressed theimportance of ground magnetometer arrays forspace weather monitoring.

•

The most recent Solar and Space Physics Decadal
Survey [Solar and Space Physics, 2013], commissionedby the National Academy of Sciences, highlighted
the role of real-time ground-based magnetometerdata as a “mainstay of the space weather enterprise,”and placed them in the context of a new modelof ground-based observations: distributed arraysof small instruments (DASI) [Distributed Arraysof Small Instruments, 2006]. Integration of datasystems and data sets was also given a high priority
in that document.

The recent Portfolio Review of the Geospace Sectionof the Division of Atmospheric and Geospace Scienceof the National Science Foundation [NSF, 2016]
specifically recognized the importance of magnetometer
arrays for research funded by both the Aeronomy andMagnetospheric branches of NSF’s AGS Division,considered how best to operate and support these arrays,

and encouraged movement toward further integration
with a recommendation that they be moved toward
funding as Geospace Science Facilities. As is the casefor other facilities supported by NSF, the science returnfrom magnetometer arrays cannot be judged simply on
the basis of their providing data to the investigatorsthat operate them; the successful operation of these
instruments and prompt, easily accessible distributionof their data is also important in providing resourcesthat other scientists can use.
The increasing demands for comparisons between
models and observations on a global scale and the related
need to provide ground magnetometer observations
promptly and efficiently to the worldwide space science
community make it imperative that the disseminationof all ground magnetometer data, as well as additional
higher level data products and summaries, be provided
in a much more accessible manner, and suggest that
new, more integrated models of organization andfunding be developed in order to do this.
In early 2016, shortly after the Portfolio Review was
first delivered to NSF, NSF-AGS personnel andmembers of the ground magnetometer community
began making plans to hold a workshop to discuss the
response of the community to the recommendationsof the Decadal Survey and Portfolio Review andsuggest steps leading to their optimal operation andscientific use. How can NSF support ground-basedmagnetometer arrays so they can more effectively andefficiently provide data (raw data and higher level data
products) to the space science community? This reportprovides the background for this workshop, held May
5-6, 2016, describes the current state of U.S.-funded
ground magnetometer arrays, and presents findings andrecommendations developed during the workshop andin subsequent communications among participants.

CHAPTER 2SCIENTIFIC VALUE OF GROUNDMAGNETOMETER ARRAYS
Arrays of ground-based magnetometers have been apart of observational space science since long before
the beginning of the space age, and they continue

Earth’s magnetic field consists of an internal
component, driven by its planetary dynamo, andexternal perturbations that result from interactionsof the internal field with the continuous but highlyvariable flow of particles and fields from the Sun(the solar wind). As with any magnetized planet, amagnetic field plays an essential role in supporting lifeon the planet by shielding its atmosphere from solar
wind ablation; indeed, the possible disappearance of a
Martian atmosphere is thought to be specifically due
to the collapse of its magnetic field.
Internal dynamo processes within the Earth create
slowly changing magnetic fields with time scalesof centuries, and transient impulses due to solar
events produce ground-level magnetic disturbancesthat can occur in minutes, by affecting the complex

Ground magnetometer observations have played amajor role in the development of space science, byremotely measuring currents that define the dynamics
of the magnetosphere and Earth’s ionosphere. They
have led to the identification of ionospheric currents
associated with magnetic substorms and storms, aswell as those associated with global compressions
4 Ground Magnetometer Array Planning

to provide essential physical context for a variety ofstudies of the ionosphere, magnetosphere, and solarterrestrial interactions.

current systems in and near the Earth’s atmosphere.
As a result, the magnetic field on the Earth’s
surface is different from location to location, and itchanges over time.
“Magnetic observatories were first established in theearly 19th century in response to the influence ofAlexander von Humboldt and Carl Friedrich Gauss.
Since then, magnetic measurement has advanced
significantly, progressing from simple visual readingsof magnetic survey instruments to include automatic
photographic measurement and modern electronicacquisition. To satisfy the needs of the scientificcommunity, observatories are being upgraded tocollect data that meet ever more stringent standards,
to achieve higher acquisition frequencies, and todisseminate data in real time.” [Love, 2008]of the magnetosphere from interplanetary shocks
and bow shock-related instabilities.
Groundmagnetometer observations have made it possible to
track and comprehend the way reconfigurations ofcurrents and convection are propagated globally after
the magnetosphere is impacted by solar wind and/orinterplanetary magnetic field dynamics. In addition,
Ground Magnetometer Array Planning 5

ground magnetometer observations continue to be used
to track energy propagation through the magnetosphere
via magnetospheric Alfven waves (including longperiod field line resonant oscillations as well as higherfrequency electromagnetic ion cyclotron waves).
Although ground magnetometers have contributed
to space science for over a century, they continue toplay an essential role. The continuous data that theseworldwide arrays provide complements the necessarily
local measurements made by orbiting research
spacecraft as well as observations from other groundbased instruments such as radars and optical imagers.
In fact, global ground magnetometer observations
provide the most fundamental and necessary context
that needs to exist if any of the current and future
missions are to provide new discovery science within
near-Earth Geospace. While their role as a continuous
monitor and context-providing source is paramount,
their continuous operation on a now-global scale
provides the means for research science at the systems
level never before possible.
Ground magnetometers continue to be the primarymeans of measuring / monitoring electrical currents
in the ionosphere, including equatorial electrojet
and auroral currents in the ionosphere, as well as themagnetospheric ring current. Magnetic perturbations
measured by these magnetometers are incorporated
into various global magnetic activity indices: Kp(planetary disturbance level), AE, AU, and AL(auroral electrojet indices, indicative of substorms
and other high-latitude disturbances), Dst, SYM/H,
SYM/D, ASY/H, ASY/D (ring current intensity andasymmetry), and PC (polar cap magnetic activity),
and also provide direct observations of geomagnetic
pulsations with frequencies ranging from 0.001 Hz
to ~ 5 Hz in the ultra-low-frequency (ULF) rangethat originate in Earth’s magnetosphere. Thesepulsations transfer energy both between regions
within the magnetosphere and ionosphere andbetween various populations of magnetosphericplasmas (including the Van Allen Radiation belts),
and also serve as diagnostics of various plasma
instabilities. These magnetometers also provide
information on the convection electric fields that
redistribute ionospheric plasma in the polar regions
and generate Joule heating of the atmosphere during
geomagnetic storms, which increases atmosphericdrag on satellites and complicates the important taskof tracking space debris [Orbital Debris: A Technical
Assessment, 1995].
6 Ground Magnetometer Array Planning

Magnetometer observations at middle and low
latitudes have also become valuable assets to monitor
and understand the electrodynamics of the ionospherethat control ionospheric plasma distributions, which
directly affect navigation and communication systems[Yizengaw et al., 2014; Anderson et al., 2004)]. For
example, the unstable plasma distributions in theequatorial ionosphere, which are mainly caused byequatorial electrodynamics, can cause disruptionsof the detection and tracking of aircraft, missiles,
satellites, and other targets; distort communication andnavigation systems [Doherty et al., 2004]; and interferewith global command, control, and surveillance
operations. At middle latitudes during geomagnetic
storms penetration electric fields can increase or
decrease ionospheric plasma densities and generatesteep horizontal gradients affecting WAAS and LAAS
navigation system accuracy. Magnetometers provide
insight into this global electrodynamic interaction of
the earth’s ionosphere and magnetic field.
Magnetometer array data have for many years also
been used as input into the Assimilative Mappingof Ionospheric Electrodynamics (AMIE) procedure[Kamide et al., 1981; Richmond and Kamide, 1988]
to characterize high latitude ionospheric electric fields,
and more recently as input into physics-based dataassimilation models of the global ionosphere suchas the various Global Assimilation of IonosphericMeasurements (GAIM) models and the Ionospheric
Dynamics and Electrodynamics Data (IDED)
assimilation model (Schunk et al., 2014)
Several additional examples of more detailed andemerging uses of arrays of ground magnetometer data
are given below:
1) Mesoscale and closely spaced two-dimensional
arrays in the auroral zone have been used todetermine the spatial distribution of field-aligned
currents (e.g., Weygand et al., [2011]), the timeand location of substorm onsets (e.g., Murphy
et al., [2009]), and the synoptic variation of themagnetospheric open-closed boundary [Urban
et al., 2011].
2) Mesoscale and closely spaced two-dimensional
arrays in the polar cap have been used to study ULF
waves in the solar wind, polar cap heating, andmagnetic coordinate systems [Urban et al., 2016]

Figure 3. (a) Toroidal oscillations of magnetospheric field lines as a result of field line resonance (FLR). Taken
from the front cover of Takahashi et al. [2006]. (b) A schematic diagram of how magnetospheric oscillations aredetected by ground-based magnetometers. A pair of ground stations separated by a distance comparable to theionospheric height can identify the gradient of wave phase due to FLR. (c) The equatorial density distributions
inferred from FLR frequencies observed by ground-based magnetometers in North America.
3) Mesoscale latitudinal arrays have been used toremotely sense the magnetospheric mass density
using field line resonance sounding (Figure 3),
including remote sensing of the radial locationof the plasmapause (e.g., Chi et al. [2013],
Boudouridis et al. [2007]).

4) Latitudinal arrays at magnetically conjugate regions
in both the northern and southern hemispherehave been used to study interhemispheric processes
and understand the way energy from the solar
wind is transmitted asymmetrically to Earth’s
high latitude regions (e.g., Kim et al. [2013, 2015],
Zesta et al. [2016]).
Ground Magnetometer Array Planning 7

5) Low latitude and equatorial latitude arrays havebeen used to monitor and study the signatures ofatmospheric tides [Tarpley, 1970a,b; Eccles et al.,2011].

et al., 2016; Fejer et al., 2007; Huang et al., 2005],
and have also been used very recently to study thedrivers of geomagnetically induced currents thatcan cause severe damage to terrestrial power grids
during major magnetic storms [Carter et al., 2015;2016], and determine their latitudinal profiles[Woodroffe et al., 2016].

6) Worldwide arrays have been used to determine
the spatial pattern and extent of ULF waves,which are often highly localized, and can appear
very differently at different locations, especiallyduring geomagnetic storms [Posch et al., 2003;
Engebretson et al., 2015], to produce a global index
of long-period ULF activity that has been used to
study the influence of these waves on radiation
belt fluxes [Kozyreva et al., 2007], and to produce
statistical maps of geomagnetic perturbations as
a function of the interplanetary magnetic field[Weimer et al., 2010] and during substorm onset
and recovery [Pothier et al., 2015].

8) Worldwide arrays are increasingly being used toprovide ground support for spaceflight missions.
This was done very successfully with THEMIS,
and there is a community effort to implement
similar support for the ICON, GOLD, and
COSMIC-2 missions [Solomon, 2016] and MMS.
With the Decadal Survey decreeing enhanced
collaboration between NASA and NSF, suchactions and mission support projects are expected
to be the norm.

7) Worldwide arrays have also been used to study theflow of energy from high latitudes to low latitudes
via waves and penetrating electric fields [Yizengaw

9) Ground magnetometer data are increasingly being
used to validate global magneto-hydrodynamic(MHD) models.

CHAPTER 3

CURRENT ORGANIZATIONAL AND
FUNDING / FINANCIAL CHALLENGES
Although magnetometer arrays over the globe aresupported by scientific agencies in many countries, thecurrent organizational and funding situation of sucharrays in the U.S. by the National Science Foundation
has not been cohesive, and is not adequate to address
current and emerging data and science needs. Rapid
progress in cyber infrastructure and capabilities has
been quickly followed by continuously increased needs
for steady provision and access to this data and related
derived products. The forefront of research requires
quick, reliable, uniform, and global access to all thesedata as well as to derivative forms (data products).
The ground magnetometer community must respondto this need with a new model of operations and data
distribution, one that supports efforts to understandionospheric and magnetospheric processes on global
scales with high spatial and temporal resolution, allwhile taking advantage of economies of scale.

Previous and current practice has led to a groundmagnetometer culture of individual array PIs using
at least 5 different kinds of fluxgate magnetometers
and two kinds of induction magnetometers (e.g.,
Figures 4-6) and developing their own data recording
systems, software, and even data formats, and leads toindividual proposers supporting both operations andscientific efforts based on that data. Magnetometer
array proposals compete in the base program against
data analysis proposals, and the cost of operations has
placed them at a disadvantage. Several U.S. arrays are inplace but are not currently funded. Unfunded existing
chains are mostly not operating and await muchneeded maintenance, which deprives the community ofvaluable data that could be maintained at relatively low
cost. While some magnetometer arrays may support
specific objectives that require only a limited durationof operation (e.g., for magnetotelluric studies of groundFigure 4.
UCLA magnetometer
sensor and GPS
antenna with cables(left) and miniaturized
Beaglebone controller/
recording system(right). These
instruments are used by
the AMBER, SAMBA,
MEASURE, andTHEMIS arrays.

8 Ground Magnetometer Array Planning

Ground Magnetometer Array Planning 9

conductivity that are important for determining
the influence of space weather on ground-induced
currents), many, if not most, magnetometer arrays
should not be viewed as something to be installed
once in a particular location and then moved to thenext location. Instead, they need to be run effectively
as a facility so there is sufficient continuity of data
to determine the optimum spatial resolution for longterm space weather monitoring tasks, for supporting
different spaceflight missions, and for providing
different necessary products.
Because of the distributed and often remote locationsof ground magnetometer sites, array teams often
face more severe logistical challenges than dolarger, more centralized ground-based instrument
teams Figures 7-9 show examples of the variety of
remote sites worldwide where U.S. - funded groundmagnetometers are currently operating.

Figure 5. Narod fluxgate magnetometer sensor (top)and controller (bottom): These instruments are used by
the USGS, GIMA (Alaska), and MACCS arrays.

The level of support for ground-based magnetometers
covers a wide range. Instruments operated by the U.S.
Geological Survey are tended by full-time personnel
who monitor the operation of the instruments andperform regular instrument checks and calibrations
consistent with standards of the INTERMAGNET
international geomagnetic observatory community.
Similarly, full-time personnel at manned U.S.
research stations in Antarctica and Greenland
monitor magnetometers at those sites to ensure thatthey are operating and recording data. However, atseveral remote sites in Antarctica magnetometers
and other instruments operate for a year or morewith no human presence, and at nearly all arrays inNorth and South America supported by the National
Science Foundation, the support of operations isprovided largely by unpaid non-scientist volunteer
operators where available, or by local institutions thatcollaborate with the PI. The result is that operations
are largely dependent on personal relationships, on
local politics and dynamics, and are inconsistent andoften difficult. A centralized entity, like a facility,that would be sanctioned by NSF would be muchbetter placed to negotiate such operations with local
institutions and have better resources to provide forsmoother and continuous operations.
Although ground-based magnetometer sensors haveoften proven to be very reliable, the instrumentationneeded to power them and record and transmit theirdata (often in harsh, remote environments) is notnearly as robust. Robert Strangeway’s experience

10 Ground Magnetometer Array Planning

Figure 6.
University of
New Hampshire
induction coilmagnetometer:
Single-axis
sensor (top) and
Full Instrument(bottom).
with ground-based magnetometers at remote sites istypical: from 10 to 20% of ground magnetometers
were damaged within 5 years after installation by either
natural (e.g., lightning) or human- or animal-caused(e.g., cutting through cables) mishaps. Untrained local
operators can be asked to check for obvious damage andreboot computers and modems after power outages, but
in most cases cannot help array managers diagnose thecause of system failures. Because of the high cost of
travel to remote sites, funding constraints thus often
result in only yearly maintenance and repair visits, thus
substantially hindering the goal of nearly constantdata coverage from each station. Travel to remotesites also puts additional pressure on low-cost groundmagnetometer projects, causing them to shift funds andtrained personnel from quality checks and database /web server development to cover necessary repairs. As

a result, the quality and continuity of data is not always
at the desired level.
Many current magnetometer sensors are over 25 years
old, but there has been little organized investment in
the U.S. in improved sensor technologies for groundbased arrays, and little attention paid to replacing aging
systems. In addition, although the sampling cadencesof most ground-based magnetometers worldwide haveincreased from typical values of 1 minute or 10 seconds
to 1 second, current arrays of fluxgate magnetometers
cannot sample rapidly enough to cover the full ULF
frequency range (EMIC waves need at least 10 Hz
sampling) because of both limited instrument sensitivity
and limited capacity of data collection and transmission
systems. Few U.S.-funded induction coil systems (withhigher sampling rates and capable of detecting EMIC
Ground Magnetometer Array Planning 11

waves) are currently in place – mostly at very highlatitudes (Table 1). (There is also possible synergy withthe atmospheric electricity community in looking at
Schumann resonances, for which sampling rates of 20
Hz or slightly higher are needed.)
Several array teams have recently developed and begun
to install upgraded data collection systems based on lowpower miniaturized single-board computers that canreadily support higher sampling cadences. It is possiblethat new technologies designed for small satellites androckets might lead to more sensitive instruments thatcan be utilized for ground-based research, but no single
instrument yet available can cover the entire frequency
range from DC to 10 Hz. More critically, we note thatthe desirability of replacing aging magnetometers andreplacing/upgrading data collection and transmission
systems so that all sites can record and transmit datawith at least a 1 Hz cadence, and do so in near real time,
has not been matched by availability of funding.

Figure 9. AMBER magnetometer sensor thatwas deployed on the premises of the Centre deRecherche Scientifique de Conakry Rogbanè(CERESCOR) in Conakry, Guinea, Africa. The

Figure 7. MACCS magnetometer sensor (inside the white box) at Cape Dorset during Arctic summer.
MACCS consists of two approximately east-west chains at 75° and 80° north geomagnetic latitude in eastern
Arctic Canada. Each system is located at an Inuit village (often near the airport, as at Cape Dorset, or otherpublic infrastructure facility) where power and local volunteer support can be provided. MACCS data wereoriginally recorded on tape cassettes mailed to the U.S. monthly; currently data are transmitted in near real time
via village wireless internet, or in two cases via the Iridium satellite telephone system.

12 Ground Magnetometer Array Planning

Figure 8. Installation of the Autonomous Adaptive
Low-Power Instrument Platform (AAL-PIP) PG5
on the East Antarctic Plateau during January 2016.
This station is the final and most equatorward of thehigh-latitude 6-station chain along the Antarctic
40-degree magnetic meridian, conjugate to Arctic
magnetometer stations along the west coast ofGreenland. The platform supports fluxgate andinduction magnetometers, dual-frequency GPS
receiver for ionospheric TEC and scintillation studies,and an HF-radio propagation experiment. Dataacquisition and station control utilize Iridium satellite
communication links. The equipment and 4-person
installation team are carried to the site via Twin Otter
aircraft and camp during the 3 - 5 day installation
period. Challenges for the installations are thelimited cargo capacity of the aircraft, aircraft range
limitations requiring the deployment of fuel caches,
limited weather information to support the aircraft
operations, and very low temperatures and very highaltitude of the AAL-PIP sites

PI of the AMBER project and an engineer from
UCLA carried out the physical deployment in August
2013. The deployment process took 3 days at thesite. The most difficult part of the installation was
to identify a magnetically quiet site close to a shelter
that has electrical power and an internet connection.
In addition to providing new science data to thebroader community from a region that had been
devoid of ground-based instruments, the AMBER
magnetometer in Conakry is the first space science
instrument ever deployed in Guinea. Thus, it enjoyedfull support from the government officials as well
as attracting considerable media attention. Since
AMBER was deployed in that country, the interest
and participation of the local community (especially
young students) to space science education andresearch has increased. Some students have alreadystarted their postgraduate studies in space science
under the supervision of professors from Cocode
University in Abidjan, Ivory Coast (another French
speaking country).

Ground Magnetometer Array Planning 13

CHAPTER 4

CHAPTER 5

ISSUES ADDRESSED AT THE
WORKSHOP

RECOMMENDATIONS OF THE
GEOSPACE PORTFOLIO REVIEWThe intent of this workshop was to suggest elements of atransition plan toward optimal operation and scientificuse of these ground arrays. Higher levels of up-timeof array stations, near real time transmission and easieraccess to data, and a variety of data products from thetraditional vector time series obtained at individual
stations to regional and/or global derived products andvisualizations, can all be expected to enhance the valueof ground-based magnetometer data, and ultimately
lead to increased understanding of Earth’s spaceenvironment.
The workshop began with the presentation of fivequestions:
1. Could technical staffing efforts from individual
smaller programs be merged to provide higher
data coverage, economies of scale, more rapid anduniform data dissemination, and continuity during
lapses of funding of individual arrays?
2. Would integrated support for maintenance acrossthe various instrument and data acquisition
platforms be possible and desirable?
3. Would new types of instruments and/or instrument
capabilities improve the scientific return frommagnetometer arrays?
4. Should operations be separated from scientificanalysis in both the organization and funding ofmagnetometer teams?
14 Ground Magnetometer Array Planning

5. Global higher level products are becoming
increasingly important, particularly in the context
of supporting other ground-based instrumentation,
spacecraft missions, and computer simulations.
How can such products best be produced anddisseminated? What additional products shouldbe generated?
Following this presentation, representatives of various
magnetometer arrays presented descriptions of thecurrent state of their programs, including locations,scientific goals and applications, technical details(sampling rates, data communications) and operational
concerns. A breakout group of array managers andengineers also discussed new sensor and data recording
systems. Other attendees discussed their uses of groundmagnetometer data and their suggestions and concerns
regarding its provision and optimal use.
Much of the second day of the workshop was devoted
to addressing proposed changes in array funding andmanagement, focusing especially on the challenges
listed in section 3; the recommendations of the
Geospace Portfolio Review (listed in section 5 below);
and examples of organization and funding models usedin other NSF-funded geoscience facilities (listed in
section 6 below).

Listed here are selected findings and recommendations
from the 2016 Geospace Portfolio Review

commissioned by the NSF [NSF, 2016]. Acronyms
used in this report are listed at the end of this section.

Chapter 6: GS Core and Strategic Grants Program“Recommendation 6.3. AER/MAG/STR grants
research also should continue to serve as a technology
incubator, funding modest‐scale projects inexperimental instrument development with a focus
on new scientific capabilities. As these development
efforts mature, their funding source should transition
from the core programs to programs such as therecommended Innovation and Vitality (Section 7.4.1)
and DASI (Section 7.4.3) programs and the CubeSat
program. The GS should also encourage instrument
development projects to seek funding through the NSFwide MRI and MREFC programs when appropriate.”(p. 55)“Recommendation 6.9. The GS should encourageand fund AER research projects, in collaboration

with the MAG community, for early development
of DASI concepts for diagnosing upper atmospheric,ionospheric and magnetospheric processes, as well as
the development of self‐consistently coupled physics‐
based models. As the DASI concepts mature, theirfunding source should migrate to the GS Facilities
program (Section 7.4.3).” (p. 57)
PR: “Recommendation 6.11. The GS should encourageand fund MAG research projects, in collaboration
with the AER community, for early development of
DASI concepts for diagnosing upper atmospheric,ionospheric and magnetospheric processes. As theconcepts mature, their funding source should migrate
to the GS Facilities program.” (p. 59)

Chapter 7: GS Facilities and Infrastructure
7.2.1 Definition of a Community Facility“The Committee found that NSF/GS does not havea clear definition of a Community Facility – what itshould provide and how it should interact with its
users. The contribution of each facility to GS program
goals and objectives does not appear to be consistently
evaluated, nor its performance in serving its user

community. The contractual arrangements between
facility PIs and NSF vary significantly from facility
to facility, and funding for science under the primary
grant or cooperative agreement of each facility also
varies significantly among the facilities. This practicehas meant that the expectations of the facilities andtheir management is not clear or transparent.”
Ground Magnetometer Array Planning 15

As a result of its examination of NSF/GS practices
regarding facilities, the Committee has identified theessential characteristics of a NSF GS facility.
“Recommendation 7.1. A facility should exhibit thefollowing functions:
1. Serve a community of users well beyond a single PI
or small group of investigators, i.e., at least national
but may be international;
2. Be operated in such a way as to ensure responsivenessto the needs of the research community to sustain
international‐class scientific productivity; thus
each facility is expected to have both an advisorygroup and a user forum, with membership notselected by facility management;
3. Operate for more than one award cycle andtypically substantially longer if warranted by the
Senior Review Process (see Section 7.8);
4. Make all data openly available and accessible ina timely fashion according to a published data
distribution and dissemination plan;
5. Develop and deliver an effective long-term plan tomaintain the facility at an international cuttingedge level;
6. Carry out a limited amount of science fundedfrom the Maintenance and Operations (M & O)
contract (see section 7.5.2);
7. Support the deployment and operations of colocated instruments with the full costs covered byeach co-located instrument Principal Investigator;
8. Deliver substantial education, outreach, anddiversity programs; and9. Provide cost-effective operations.” (pp. 74-75)
Comments of the appropriateness of this list to
proposed ground magnetometer facilities are presented
in section 9 below.
7.2.3 Class 1 and Class 2 Community Facilities“The PRC found it helpful to consider the Community
Facilities in two classes. A Class 1 facility is a major,
complex facility at a single site. Its investment
over time typically reaches many $10sM, requires
significant M&O funds and accommodates a varietyof complementary instruments at or very near the site.
Class 1 facilities might be expected to have a lifetimeof 20+ years from first deployment. In the current
16 Ground Magnetometer Array Planning

portfolio, all the incoherent scatter radars (ISRs) areconsidered to be Class 1.
“Class 2 facilities are more modest and diverse
investments. They include distributed networks of
instruments that are simpler to operate than ISRs(e.g. SuperDARN), facilities producing value‐
added products from data from other sources (e.g.
SuperMAG and AMPERE), model support for thecommunity (e.g. CCMC) and data management(Madrigal Database, currently funded through theMillstone Hill ISR contract).” (p. 75)
7.3.4
Class 2 Facilities:
recommendations

Findings and“Finding. Several magnetometers and magnetometer
arrays are funded through research projects.
“Recommendation 7.16. The GS should assess if theera may now exist wherein greater scientific synergies
and optimization of operations could be obtained if
all GS‐sponsored magnetometers were managed asa single array. Such an array could thus evolve into aClass 2 facility (see Section 7.4.3 for more details on
DASI).” (p. 81)
7.4.3 Distributed Arrays of Small Instruments(DASI)“The DASI concept was recommended in the first
decadal survey of solar and space physics research The
Sun to the Earth and Beyond: A Decadal Research Strategy
in Solar and Space Physics (2003). DASI would provide
the temporal and spatial coverage of many atmosphericand ionospheric parameters that complement
measurements from other ground‐ and space‐based
facilities.
The DASI concept was subsequently
examined by a National Academies workshop.25
25 http://www.nap.edu/catalog/11594/distributed‐arrays‐of‐small‐instruments‐for‐solar‐terrestrial‐research‐report“In the last decade, the DASI concept has not evolved
as rapidly as originally envisaged. This shortcoming
has been due to a variety of factors, including a lackof funding opportunities, inadequate community
experience in cultivating the required international
collaborations, and inadequate experience in developing
robust capabilities for unmanned and energy‐efficient
operation of distributed instruments and for automateddata processing, analysis and transfer. Nevertheless,some members of the US scientific community haveforged ahead with the development and improvementof new ground‐based instrumentation and thedeployment of small networks. These activities havebeen sponsored by diverse funding streams including
NSF MRI, GS Core, the Office of Naval Research,and the Department of Defense University ResearchInstrumentation Program (DURIP).
…
“The types of instruments deployed in DASI‐type
networks include but are not limited to Global
Positioning System receivers giving total electron
content (TEC) and scintillation activity, Fabry‐Perot
interferometers measuring winds and temperaturesat mesospheric and/or thermospheric altitudes,

magnetometers, meteor wind radars, digital ionosondes,
LIDARs, optical imagers, photometers, riometers and
VLF radio receivers.
“Finding. With growing recognition for the importance ofgeospace system science, the geospace community can expect,in the next decade, an increasing demand for higher spatial
and temporal resolution in measurements, not only todetermine the local, regional and global scale of processes but
also for data assimilation into geospace models.
“Recommendation 7.24. The GS should createa “DASI” fund with two purposes: (i) to develop
and build new “small” instrumentation suitable for
deployment in a DASI network and (ii) to provide
M&O funds to maintain the network once created.”(p. 84)

Chapter 8. Partnerships and Opportunities
8.3 International Partnerships“Finding. US funding for engagement in international
partnerships provides excellent leverage for
additional data, access to an expanded base of scientific andtechnical skills and knowledge, and to
new and innovative software and hardware. Significant
benefits accrue to all partners.” (Examples included
SuperDARN and the MACCS magnetometer array.
Other examples could include SAMBA, AMBER, LISN,
THEMIS GMAG, and various international partnerships

for U.S.-built induction magnetometers, which alreadyinvolve the U.K., Norway (Svalbard), South Korea, andGermany.
“Recommendation 8.16. The GS should continue tosponsor highly-rated proposals to develop, deploy,and operate new instruments, instrument networks
and data acquisition, especially when GS resources
for the project are leveraged through international
partnerships.” (p. 103)

Chapter 9. Recommended GS Portfolio
9.4 GS Facilities Program“The DRIVE initiative of the DS directs NSF to provide
funding sufficient for essential synoptic and multiscaleobservations. Distributed measurements are required
to provide synoptic ground based observations ofgeospace phenomena. DASI networks can fulfill thisrequirement. The recommended portfolio includes an
explicit line item for DASI development, deployment
and operation.

“Recommendation 9.12. The GS should create a
new DASI Facilities Program with a $1.6M annual
budget. This fund should be used initially to develop
and implement one or more DASI Class 2 facilities
with concept selection determined by peer review.
For a fully operational DASI to transition to a Class
2 facility, it must satisfy the criteria for a community
facility as defined in Section 7.2.” (p. 110)

Ground Magnetometer Array Planning 17

List of Acronyms and Abbreviations used in the Geospace Portfolio Review
AER
AGS
AMPERE
CCMC
DASI
DS
DRIVE

Aeronomy program, within NSF’s
Geospace Section
Division of Atmospheric andGeospace Science of the National
Science Foundation

Active Magnetosphere and Planetary
Electrodynamics Response
Experiment
Community Coordinated ModelingCenterDistributed Arrays of Small
Instruments for Solar-Terrestrial
Research

Solar and Space Physics Decadal
SurveyDiversify, Realize, Integrate,
Venture, Educate

GS

ISR

MAG
MREFC
MRI
M&O
NSF

PRC
STR

Geospace Section of the Division of
Atmospheric and Geospace Science(AGS) of the National Science
Foundation
Incoherent Scatter Radar

Magnetospheric Physics program,within NSF’s Geospace Section
Major Research Equipment andFacilities Construction

Major Research Instrumentation
Program
Maintenance and Operations
National Science Foundation

Portfolio Review Committee

Solar-Terrestrial Research program,within NSF’s Geospace Section

CHAPTER 6

EXAMPLES OF GOVERNANCE AND
ORGANIZATION IN OTHER SCIENTIFIC
FACILITIESIn this section we review four examples oforganizations currently funded by NSF tocoordinate distributed scientific instruments andresearch programs: EarthScope, IRIS, UNAVCO,
and SuperDARN. Only SuperDARN falls within
the GS branch of NSF. The others, however, deal
with small, distributed sensors.
6.1 EarthScope:
EarthScope is a program of the National Science
Foundation that deploys thousands of seismic,
GPS, and other geophysical instruments tostudy the structure and evolution of the North
American Continent and the processes thatcause earthquakes and volcanic eruptions. It
comprises three interlinking components: 1) the
EarthScope Facility operated by the UNAVCO
and IRIS consortia (see below), 2) a research
program that supports PI-led investigations,and 3) an investigator community, coordinatedby an academic EarthScope National Office,that actively participates in science planning,
research, and facility governance. The EarthScope
National Office (ESNO) is a rotating, universitybased organization that facilitates scientific planningand coordinates education and outreach efforts for the
EarthScope community. The ESNO also organizes the

18 Ground Magnetometer Array Planning

EarthScope National Meeting and several scientificworkshops held throughout the year, supports andfacilitates EarthScope Synthesis Workshops, provides
opportunities for community planning, and maintains
and updates an EarthScope web site to highlight key
science, education, and outreach results.
6.2 IRIS (Incorporated Research Institutions for
Seismology)
IRIS is a nonprofit consortium of over 120 US
universities dedicated to the operation of sciencefacilities for the acquisition, management, anddistribution of seismological data.
The IRIS
governance and management structure is an interface
among the scientific community, funding agencies, and
IRIS programs. The structure is designed to ensure
close involvement of the research community in thedevelopment of IRIS facilities, focus scientific talenton common objectives, encourage broad participation,and effectively manage IRIS programs. Each year, over
50 scientists from member institutions participate in
IRIS management through its Board of Directors,
eight regular committees, and ad hoc advisory groups.
Standing committees maintain community oversight
while program managers are responsible for dayto-day activities. Committee scientists work with aprofessional staff at IRIS led by the President, Directorof Planning, Director of Project Administration,
Director of Finance and Administration, and the five
Ground Magnetometer Array Planning 19

program managers. Representatives of the full set ofmember institutions elect the nine-member Board of
Directors. IRIS also maintains an Advisory Council,
Science Advisory Committees, and a Coordinating
Committee.

Comparison of SuperDARN and
Ground-based Magnetometer Arrays•

6.3 UNAVCOUNAVCO was created in 1984 in response to thechallenge of applying GPS to geosciences. At that time
it was called the University NAVSTAR Consortium.
Managed by a Board of Directors, UNAVCO
periodically develops a Strategic Plan, and provides
GPS/GNSS receivers, seismometers, tiltmeters,
etc. for purchase or loan. Following installation,
UNAVCO tests and troubleshoots the instruments
and the data collection, power and communications
systems required to record and access data fromcontinuously operating and often remote sites. It also
provides network monitoring for several networks
from which UNAVCO downloads data. UNAVCO
has three Standing Committees (Audit and Finance,
Nominating, Membership), five Advisory Committees
to the Board (Education and Community Engagement,
Geodetic Data Services, Geodetic Infrastructure, Polar
Networks, and WinSAR Executive Committee), andtwo Working Groups (COCONet and Terrestrial
Imaging Geodesy).

•

Their data are important for a big-picture
view of Magnetosphere-IonosphereThermosphere coupling processes.

•

Their measurements relate directly tofundamental ionospheric parameters(electric fields and currents).

•

They are different in terms ofdevelopment path - all SuperDARN
radar designs derive from the originalradar (Goose Bay) and new groups
have adopted the established operating
and software protocols. Groundmagnetometer arrays have developed
largely independently; they use 5
different types of fluxgate instruments,
many different types of controllers anddata recording systems, produce data inseveral different formats and at different
sampling rates, and provide their data
mostly via a number of array-specific web
sites.

6.4 SuperDARN
The U.S. portion of SuperDARN (the Super Dual
Auroral Radar Network) is a recognized Class 2
facility, consisting of a collaboration of 4 institutions(Virginia Tech, JHU/APL, Dartmouth College, andthe University of Alaska Fairbanks), for which one
collaborative proposal is written. This base award
from the Space Weather Research Program covers theoperation of about 10 HF coherent-scatter radars, theprocessing and distribution of data to SuperDARN
partners, and the provision of support to data users,
in addition to modest amounts for developing new
research lines with the data. The scientific staff of
the SuperDARN groups separately pursue support
for research from NSF, NASA, and other sources inboth base and targeted programs. Economies of scale
are realized in that technical progress by one group
benefits the others and there are notable leveraging
benefits in that the U. S. partners and the U.S. researchcommunity gain access to the entire SuperDARN dataarchive which is generated from about 35 radars. The
costs of the non-U.S. operations are supported by the
20 Ground Magnetometer Array Planning

Both are examples of distributed, alwayson, arrays of distributed instruments that
produce a uniform ‘product’.

•

They are also vastly different in the fieldsof view of individual instruments: eachground magnetometer has an effective
omnidirectional range of ~100 km, while
each SuperDARN radar has a radial
range from 180 km to ~3500 km and an
azimuthal range of ~30°-60°.

•

Web tools exist to facilitate viewingof all SuperDARN data and higher
level products (by both experts andnon-experts). With the exception ofSuperMAG, ground-based magnetometerdata are consulted in a more ad hoc anddisjointed way.

funding agencies of the other participating countries.
Importantly, the partners agree on common protocols
for operating the radars and processing the data into asingle shared format.
Internationally the SuperDARN collaboration is
managed by the SuperDARN Executive Council,
which is comprised of Principal Investigators (PIs)from the partner nations. The Executive Council
oversees the joint operations of the radars, implements
new initiatives brought forward by the various working
groups and individuals, and ensures timely access forusers to high quality data. The SuperDARN Principal
Investigators’ Agreement specifies that the PIs are
responsible for one or more SuperDARN radars,
managing all radar operations in the various countries,
leading the engineering and technical teams, handling
day-to-day radar operations, raising necessary funds,
and are to be the point of contact for users. The
Executive Council holds a face-to-face meeting at theannual international SuperDARN workshop.
The annual workshop is the principal venue for the
PI Council to coordinate the activities of various
working groups that maintain consistency acrossthe collaboration. These include working groups tocoordinate radar scheduling, data distribution, andcoordination with satellite missions.The working groups
operate year-round and maintain communications
by emailing and dedicated web sites. They are also

tasked with developing and testing new experimental
capabilities and ensuring high data quality and reliabledata distribution and archiving.
6.5 Polar Engineering Development Center (PEDC)
The PEDC, housed at the New Jersey Institute ofTechnology (NJIT) and operating collaboratively
with Merrimack College and the University of New
Hampshire, consists of collegiate professors, researchscientists, electrical and mechanical engineers, andtechnicians experienced in instrument and hardware
design for deployment in high latitude/polar regions.
The original group was formed in the 1980s as part of the
NSF-supported Automatic Geophysical Observatory(AGO) program which operates to this day on projects
active across the Antarctic ice shelf. The PEDC is acommunity resource for the Antarctic astrophysicaland geospace communities, thus serving the analogous
role that the UNAVCO or IRIS-PASCAL programs
serve to the Antarctic Earth Sciences Program, by
providing support in the areas of (a) sustainable “green”
power generation in the 10-W to 100-W range, (b)power conditioning and control, (c) robust engineeringfor polar climates, (e) data acquisition techniques, units,
and transmission services, and (f ) general polar field
support. Many of the U.S. Antarctic magnetometersystems are currently operated by the PEDC.

Ground Magnetometer Array Planning 21

Figure 10. Sketchof a possible interim
organizational
structure for the U.S.
ground magnetometer
community, adaptedfrom a diagram
developed by Dr. Andy
Gerrard of the New
Jersey Institute ofTechnology.

CHAPTER 7

FINDINGS AND RECOMMENDATIONS
Making the transition to a Class 2 groundmagnetometer facility, following current examples
such as SuperDARN, will involve changes in theorganization and funding of P.I.-led magnetometer
arrays, but brings the promise of achieving criticallyimportant long-term stability and scientific productivity
for these arrays, including the development of an easily
accessible, long term archive of the data. At the mostbasic level, this involves splitting facility/operations
budgets from science budgets for each magnetometer
array. In the near term, facility/operations budgets
might themselves be split or divided out, so that PIs
install and maintain the hardware, while one or two
categories of cooperative organizations – a “diagnostics
and response unit” and an “augmented data center”– would be responsible for monitoring of routine
operations (data recording and transmission) andstorage and distribution of data and production of data
products, respectively.
Suggested Initial Steps (within months)
1. Increase coordination among array managers via
blogs, e-mail lists, or similar easy-access means
regarding operational issues such as coordinationof repair and maintenance visits and technicalissues such as development of new miniaturized
data systems and compatible data formats. Also
increase discussions of these matters with thewider user and instrument communities and NSF
staff in the Division of Atmospheric and Geospace
Sciences (AGS, Aeronomy, Magnetosphere) and
Office of Polar Programs (OPP).
22 Ground Magnetometer Array Planning

2. Encourage individual array programs to prepare
data in standard formats and to transmit themin near real time (if this is not currently done) todata centers such as SuperMAG, THEMIS, and
CDAWEB. Efforts to achieve these objectives, if
needed, should be part of any renewal proposals
for funding in the near future.
3. Proposals for renewed funding of magnetometer
arrays in the near future should clearly designate
facility/operations budgets and person-months
separately from science budgets.
4. Schedule a followup workshop for all members of
the ground magnetometer array community, tobe held during or immediately before or after thesummer 2017 GEM Workshop, to develop plansfor implementing the near-term steps below.
Near-term Steps (1-3 years)
1. Establish a Ground Magnetometer Array Advisory
Board (4-6 members) tasked to periodicallyevaluate the operations and effectiveness of all
U.S.-funded ground magnetometer arrays, suggest
possible additional magnetometer locations in
consultation with USGS and the international
ground magnetometer community (including
ULTIMA), and develop plans in conjunction
with NSF-AGS, NSF-OPP, and the groundmagnetometer community to transition toward
more complete implementation (as appropriate)of the DASI model, leading toward partial or full

funding of arrays from the Geospace Facilities
Program. (Portfolio Review recommendations
6.9, 6.11, and 7.16) As was pointed out in that
review, further studies are needed to quantify thecost/benefit value, if any, of multi-instrument
DASI networks: feeding data from various typesof sensors into a common power, data recording,and data transmission system, either at remotesites (often at high latitudes and/or in extreme
environments) or at less challenging locations.
2. Fund a team, selected by the Advisory Board, via asmall grant to gather information about operationalcosts of all NSF-supported magnetometer arrays,
including person-months; instrument downtime and causes; mode of data transfer; and useof array data, including number of publications.
The funding logistics could be satisfied by a small
supplement to an existing grant.
3. Provide sufficient support to SuperMAG to enable
it to ingest, store, and serve the full set of data fromboth fluxgate and induction coil magnetometers, attheir original sampling rates (currently only 1-min
data are provided by SuperMAG).

4. Develop and fund one (or a small number ofregional) Ground Magnetometer Diagnostics
and Response Units (GMDRUs) that sharecommon technologies (e.g., instrument types andmanufacturers) or geographic regions (e.g., polar,
midlatitude, low latitude). These Units will support
operations and data transmission of all U.S.-funded
ground magnetometer arrays currently supported
only by grants to individual arrays. GMDRU
personnel will monitor instrument operation, data
quality, and volume of data transmitted on a daily
basis, and notify responsible array personnel of any
problems. Because it is not immediately clear how
such a transition will work for each GMDRU, it
was considered inadvisable at the outset to movethe responsibility of performing necessary repair
and maintenance tasks at individual sites fromthe current array management to its GMDRUs,
but we recommend a transition toward thisend. As part of this step, we recommend that
the Ground Magnetometer Array Advisory
Board develop a set of metrics to measure theperformance of GMDRUs and any improvements
in array function that they contribute.
Figure 10 shows a possible transitional
Ground Magnetometer Array Planning 23

configuration. Three (or more) magnetometer
array groups receive monitoring and maintenancesupport from a GMDRU, and either directly or via
the GMDRU they transmit their data to a central
repository such as SuperMAG that also prepares
derived data products, and makes all the data easily
available to the geospace community. Initiallyseveral array groups and GMDRUs may form;
initial experience with these configurations, as well
as optimization studies, may lead to modifications
as the ground magnetometer community moves
toward a more unified operational structure.
5. Make funds available to ground magnetometer
array projects to reimburse local hosts (currently
often unpaid volunteers) for their support ofmagnetometer systems at remote sites.

Review Recommendation 6.3)
For fluxgate
magnetometers this would include higher sampling
rates, lower noise and digitization levels, andideally miniaturized footprint, lower power, andenvironmentally robust operation (e.g, for use inpolar regions and at remote sites). In the ideal casea single instrument would provide both vector andtotal field (scalar) measurements with high accuracy,
and be used to replace the currently separate vector(fluxgate and induction coil) and scalar instruments
at magnetic observatories worldwide.
Longer-term Steps (5-10 years)

6. Either in the GMDRUs or as a whole, the groundbased magnetometer community should consider
the possibility of moving toward a standardized
raw data format, and if the move to single-board
systems running variations of the unix operating
system permits, consider developing a “Mag OS”
magnetometer operating system that all teams
could use.

1. Develop and fund one or more Class 2 facilities
to operate, monitor, and maintain all NSF-funded
ground-based magnetometer arrays (Program
Review recommendations 6.9, 6.11, and 7.16). Stepsin this direction are already underway within the
U.S. Antarctic Program (e.g., the Polar Engineering
Development Center). The creation of GMDRUs
will be an initial step in this direction and, if
successful, will enable the ultimate creation of theoverall Class 2 facility or facilities. Planning forthis/these facilities should also take into accountthe necessity of working with international partners(Program Review recommendation 8.16).

7. Develop, in conjunction with the emerging
DASI community and the magnetic observatorycommunity, additional global higher level products
to support scientific efforts using other groundbased instrumentation, spacecraft missions, andcomputer simulations, and enable them to be
displayed using community-supported graphic
tools such as Autoplot.

2. Provide funding to install improved, identicalmagnetometer sensor, recording, and datatransmission systems to the extent that this isfinancially and logistically feasible. (As longas equipment continues to vary from one arrayto another, the effectiveness of a single Class 2
facility in operating, monitoring, and especiallymaintaining all participating arrays will bediminished.)

8. Encourage efforts to develop improved groundmagnetometer array systems (sensors, data
recording and storage computers, data transmission
technologies and protocols) through both existingand possibly new NSF funding channels. (Program

3. Continue to develop global higher level data
products to support scientific efforts using
other ground-based instrumentation, spacecraft
missions, and computer simulations. (See the next
section for examples of such products.)

24 Ground Magnetometer Array Planning

CHAPTER 8

DERIVED DATA PRODUCTS
Global and higher level data products such as Kp, AE,
and Dst, based on ground-based magnetic field data havefor many years been used for both quick-look and morein-depth studies of magnetospheric and ionosphericphenomena. They can be used in support of studies
using other ground-based instrumentation, spacecraft
missions, and computer simulations. Although theseearlier indices were derived using only a small number ofstations, advances in data communications and increases
in the number of magnetometers worldwide in the past
decade make it practical to generate additional indicesand more complex data products. The SuperMAG
team has used worldwide ground magnetometer data
to develop indices utilizing many more stations than
the standard auroral electrojet indices (SuperMAG
SME, SMU, and SML vs. AE, AU, and AL).
Visual / graphical products have significant value to thespace physics community both as quick-look indicatorsof activity and as detailed displays of spatially extended
scalar and vector variations. Products developed bySuperMAG also include graphical displays such as
Figure 2 showing, for example, ionospheric convection(derived from magnetic perturbations) and auroral
activity.

Higher-level Data Products
Scientific Value of Higher-level Products•••

Provides basis for large-picture, systemlevel science for showing connections
between domains
Assists in developing first-principles
MHD models
Enables space weather science andapplications

Helpful Attributes of Higher-level
Products:•••

Easy to access and understand
Underlying data are available for morerefined analysis
Supported by easily accessible expertise (aknowledgeable person)

Ground Magnetometer Array Planning 25

Possible additional data products:
a. Global field-line resonance-based calculations ofmass density as a function of L and local time (e.g.,
extensions of those shown in Figure 3), including
location and characterization of the plasmapause.
b. SuperMAG currently produces its own versionsof the auroral electrojet indices AE, AU, and AL,
designated SME, SMU, and SML. It could also
produce local time indices, and regional K indices(regional activity indices specifying localized
activity across a particular area over earth).
c. Global equivalent currents and electrojets,
equatorial and auroral electrojet variability inlongitude, and possible regional products.
d. Routine production of spatial plots (maps) of
simultaneous data from magnetometers and other
instruments such as the SuperDARN radars.
e. Maps of the synoptic open/closed boundary of
the magnetosphere.
f.

Quick-look global maps (magnetic keograms)of perturbations and ULF waves: “Is there
any activity? Where?” Maps of ∆B and Pc5
wave amplitudes (broadband, narrowband,or combined, possibly using the ULF index
database), EMIC waves, etc. Also, stacked plotsof time series of “virtual magnetometers” at fixed
local times.

g. Comparisons of interhemispheric perturbations;conjugate maps of electrojet currents, ULF wave
activity at least in the Pc5 band, and at least at
well-instrumented longitudes; conjugate maps ofcusp and substorm phenomena.
h. Development of more ‘interpretive’ capabilities
such as automated identification and location ofsubstorms and Pi2s.
i.

Joint data products with USGS for Space
Weather diagnostics, and that the global GIC(ground-induced currents) community can use.
(INTERMAGNET routinely provides timeseries plots of dB/dt at each station.)j.

Shared software tools for analysis of magnetometer
data, as is done, for example, in the seismic andastrophysical communities. These might include
standardized error detection and mitigation
software for secular variation baseline jumps anddrifts. (See the example of Quakefinder, which
has deployed a network of induction coil systems
to search for earthquake precursors.)

CHAPTER 9

CLASS 2 FACILITY CONSIDERATIONS
As noted in section 5 above, the Portfolio Review
included a proposed list of nine items that would
characterize every Facility, presumably both Class 1
and Class 2, supported by NSF-AGS. In this section
we briefly note our understanding of the potential fit ofboth A) the proposed GMDRUs, and B) a full groundmagnetometer array DASI structure:
1. Serve a community of users well beyond a single PI
or small group of investigators, i.e., at least national
but may be international. A: No B: Achievable
2. Be operated in such a way as to ensure responsivenessto the needs of the research community to sustain
international‐class scientific productivity; thus eachfacility is expected to have both an advisory group
and a user forum, with membership not selected byfacility management; A,B: Achievable for both
3. Operate for more than one award cycle andtypically substantially longer if warranted by the
Senior Review Process (see Section 7.8). A,B:
Achievable for both
4. Make all data openly available and accessible
in a timely fashion according to a publisheddata distribution and dissemination plan. A,B:
Achievable for both

26 Ground Magnetometer Array Planning

5. Develop and deliver an effective long-term plan tomaintain the facility at an international cuttingedge level. A,B: Achievable for both
6. Carry out a limited amount of science fundedfrom the Maintenance and Operations (M & O)
contract (see section 7.5.2). A,B: This task seems
more appropriate for Class 1 Facilities.
7. Support the deployment and operations of colocated instruments with the full costs covered byeach co-located instrument Principal Investigator.
A: No B: Achievable
8. Deliver substantial education, outreach, anddiversity programs. A,B: This task seems more
appropriate for Class 1 Facilities.
9. Provide cost-effective operations. A,B: Achievablefor both
One additional task of the Ground Magnetometer
Array Advisory Board or its successor will be to workwith NSF-AGS staff to develop an appropriate andfeasible version of the above list that can be used
to guide the operations and management of the
GMDRUs and future full ground magnetometer array
DASI structure(s).

Ground Magnetometer Array Planning 27

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30 Ground Magnetometer Array Planning

Ground Magnetometer Array Planning 31

U.S. GROUND-BASED MAGNETOMETERWORKSHOP PARTICIPANTS

ARRAYS AND PROGRAMS AS OF FALL 2016

Robin Barnes
Johns Hopkins University
Applied Physics Laboratory

Array

Location

Instruments

Manufacturer

No. of Locations

AAL-PIP

Antarctica
Antarctica
AfricaSouth America
East Asia
Continental US
AlaskaContinental US
South America
South America
Arctic CanadaCont. US & Mexico
Cont. USSouth America
Antarctica
CanadaU.S. & Territories
Antarctica
Antarctica
Alaska, Canada,
Greenland, Svalbard
Antarctica

Fluxgate
Induction coil
Fluxgate
Fluxgate
Fluxgate
Fluxgate
Fluxgate
Fluxgate
Fluxgate
Fluxgate
Fluxgate
Fluxgate
Fluxgate
Fluxgate
Fluxgate
Fluxgate
Fluxgate
Fluxgate
Induction coilInduction coil

Korepanov
UNH
UCLA
UCLA
UCLA
UCLA
Narod
UCLA
UCLA/Jicamarca
Jicamarca
Narod
UCLA
UCLA
UCLA
UCLA
UCLA
Narod
Bell Labs
Tohoku U.
UNH/Augsburg

6
6
7
2
4
6
9
2
4
6
8
9
6
7
3
22
14
7
5
8

Induction coil

UNH/Augsburg

3

AMBER/iMAGS
Falcon
GIMA
IGPP-LANL
Jicamarca
LISN
MACCS
McMAC
MEASURE/iMAGS
SAMBA/iMAGS
THEMIS
U.S. Geological Survey
NJIT / AGO
MICA - North
MICA - SouthAthanasios Boudouridis
Space Science InstitutePeter Chi
University of California at Los Angeles
Robert Clauer
Virginia Polytechnic Institute andState University
Vince Eccles
Space Environment Corporationand Utah State University
Mark Engebretson
Augsburg College
Carol Finn
U.S. Geological Survey
Andy Gerrard
New Jersey Institute of Technology
Jesper Gjerloev
Johns Hopkins University
Applied Physics Laboratory
Donald Hampton
Geophysical Institute
University of Alaska – Fairbanks
Michael Hartinger
Virginia Polytechnic Institute andState University
Hyomin Kim
New Jersey Institute of Technology

Matt Magoun
Boston College
John Meriwether
National Science Foundation
Mark Moldwin
University of Michigan
David Murr
Augsburg College
Musko, Stephen
University of Michigan
Shin Ohtani
Johns Hopkins University
Applied Physics Laboratory
Mike Ruohoniemi
Virginia Polytechnic Institute andState University
Erik Steinmetz
Augsburg College
Robert Strangeway
University of California at Los Angeles
James Weygand
University of California at Los Angeles
Zhonghua Xu
Virginia Polytechnic Institute andState University
Endawoke Yizengaw
Boston College
Eftyhia Zesta
NASA / Goddard Space Flight Center

Janet Kozyra
National Science Foundation
Marc Lessard
University of New Hampshire

32 Ground Magnetometer Array Planning

Ground Magnetometer Array Planning 33

LIST OF GROUND MAGNETOMETER ARRAY WEB SITESACKNOWLEDGEMENTSSERVING MAGNETOMOETER DATA
AAL-PIP

http://mist.nianet.org/index.html

Antarctic Geospacehttps://antarcticgeospace.njit.edu/

CDAWEB

http://cdaweb.gsfc.nasa.gov/

GIMA

https://www.asf.alaska.edu/magnetometer/

INTERMAGNET

http://www.intermagnet.org/data-donnee/download-eng.php

LISN

http://lisn.igp.gob.pe/

MACCS

http://space.augsburg.edu/maccs/index.html

The information provided in this report is the result of a 2-day workshop held inGreenbelt, Maryland, May 5-6, 2016, and of a follow-up meeting held in conjunction
with the 2016 AGU Fall meeting in San Francisco, CA. The personnel listed above
attended this workshop and many provided written contributions to the report. We
are grateful for the financial support provided by the National Science Foundation
for the workshop and this publication, and for the work of Jennifer Posch in planningthe meeting logistics and Mark Chamberlain for the graphic design and productionof this report. We thank J. J. Love and many workshop participants for reading draft
versions of this manuscript.

Search Coils (Augsburg) http://space.augsburg.edu
Search Coils (UNH)

http://mirl.sr.unh.edu/projects_ulf.html

SAMBA-AMBER

http://magnetometers.bc.edu/index.php/78-magnetometers/78-home

USGS

http://geomag.usgs.gov/products/

SuperMAG

http://supermag.jhuapl.edu/

THEMIS GMAG

http://themis.ssl.berkeley.edu/data/themis/thg/mirrors/mag/World Data System

http://wdc.kugi.kyoto-u.ac.jp, http://www.wdc.bgs.ac.uk

34 Ground Magnetometer Array Planning

Ground Magnetometer Array Planning 35