***The following was extracted from the Space Weather Architecture Study Final Report
Background document, a draft of which is located on the Space Weather Architecture Web Page
(URL: www.virtualproject.com).***
1.1 CURRENT AND EVOLVED BASELINE
The ORWG documented the current and evolved space weather baseline as the basis for
developing and assessing future candidate architectures. The current baseline identifies space
weather data sources, processing tools, products, customer base, and requirements as of 1998.
The evolved baseline projects current capabilities through 2010. It is based on the assumption
that approved plans for modification and new or upgraded capabilities will be implemented on
schedule. Both of these baselines contain elements from the civil and international communities.
1.1.1 Space-Based Sensors
1.1.1.1 Defense Meteorological Satellite System (DoD)
(Current Baseline) The DMSP mission is to provide an enduring and survivable capability to
collect and disseminate global visible and infrared cloud data and other specialized
meteorological, oceanographic, and solar-geophysical data. These data support worldwide DoD
operations and high priority programs. Normally two operational DMSP satellites occupy Sunsynchronous, near-polar, circular orbits with an altitude of about 840 km, a period of 101.6
minutes, and an inclination of 98.75°. Each satellite scans a swath about 2,900 km wide and
covers the Earth in about 12 hours.
The DMSP Special Sensor Precipitating Electron/Proton Spectrometer (SSJ/4) measures the ions
and electrons that precipitate into the ionosphere and produce aurora. The SSJ/4 measures ion
and electron fluxes using four electrostatic analyzers, each with 20 channels detecting particles
with energies ranging from 30 eV to 30 keV. These data can identify the location of active
aurora and provide an objective measure of the level of any disturbance in the Earth's magnetic
field (expressed in terms of the "Q index").
The DMSP Special Sensor for Ions, Electrons and Scintillation (SSIES-2) measures ionospheric
parameters such the ambient electron and ion densities and temperatures, plasma irregularities,
and plasma drifts at the altitude of the satellite orbit in the vicinity of the DMSP spacecraft. The
DMSP orbit (about 840 km) is well above the F2 region peak, so the electron density at this
altitude cannot be measured using conventional ground-based vertical incidence ionospheric
sounders. Therefore the electron densities measured by the DMSP SSIES-2 provide a basis for
the topside ionospheric electron density profiles.
The DMSP Special Sensor Triaxial Fluxgate Magnetometer (SSM) measures geomagnetic
fluctuations at the altitude of the DMSP orbit. This data can be used to determine the boundaries
of currents flowing into and out of the ionosphere. The combination of data from the SSIES,
SSJ/4, and SSM provide data for specification of the heating and dynamics of the ionosphere and
neutral atmosphere. The DMSP Operational Line Scan sensor provides nighttime visual aurora
images and can be used to help determine the location of the equatorial boundary of the auroral
oval.
(Evolved Baseline) Some DMSP Block 5D-3 satellites are likely to be operational in 2010. The
space weather enhancements of the Block 5D-3 over the current baseline include addition of:
 Special Sensor Ultraviolet Limb Imager (SSULI). SSULI, an optical
sensor developed by Naval Research Laboratory (NRL), measures




vertical profiles of the natural airglow radiation from atoms, molecules,
and ions in the upper atmosphere and ionosphere. It does this by
viewing the Earth’s limb at a tangent altitude of approximately 50 km to
750 km. SSULI measures from the extreme ultraviolet (EUV) to the far
ultraviolet (FUV) over the wavelength range of 80 nm to 170 nm, with
1.5 nm resolution. New science algorithms will process SSULI
observations to determine atmospheric composition.
Special Sensor Ultraviolet Spectrographic Imager (SSUSI). SSUSI
is a remote-sensing instrument that measures ultraviolet (UV) emissions
in five different wavelength bands from the Earth’s upper atmosphere.
SSUSI will be mounted on a nadir-looking panel of the DMSP 5D-3
satellite. The multi-color images from SSUSI cover the visible Earth
disk from horizon to horizon and the anti-sunward limb up to an altitude
of approximately 520 km. The UV images and derived environmental
data provide near-real-time information, which can be used in many
applications. Initial Operational Capability (IOC) for SSUSI/SSULI on
DMSP Block 5D-3 is 2001.
Precipitating Electron/Proton Spectrometer Upgrade (SSJ/5). SSJ/5
detects low energy proton and electron data by measuring downward
fluxes of charged particles along the earth's magnetic field lines. The
upgraded SSJ/5 will provide additional data to derive an estimate of the
total energy being deposited into auroral regions.
Enhanced Ionospheric Plasma Drift/Scintillation Monitor (SSIES3). SSIES-3 provides in-situ plasma drift, scintillation, and electron
density. These data may also be available via an Asynchronous
Transfer Mode (ATM) link providing Air Force Weather Agency data
directly to Schriever AFB. This link is expected to operate at 45 Mbps
with possible expansion to 155 Mbps.
Triaxial Fluxgate Magnetometer (SSM). SSM will measure Joule
heating and the shape of the topside ionosphere by locating regions
where currents flow horizontally. Data are available; however, they are
not disseminated to SEOC because there are no algorithms in place to
display or employ the data in numerical models.
1.1.1.2 Global Positioning Systems/Nuclear Detonation Detection System (DoD)
(Current Baseline) Some of the Global Positioning System (GPS) satellites carry an instrument that
measures the energetic particle radiation at the GPS satellite’s orbital altitude. This instrument collects
data at fixed-time intervals, stores it, and transmits to the ground control segment when commanded.
This includes 7 channels of electrons (200 keV to >5 MeV) and 11 channels of protons (6 MeV to > 50
MeV). Currently, the instrument is only flown on every sixth satellite. The intent is to have an
operational dosimeter in each of four orbital planes. The orbits of the satellites are ideally suited for
monitoring the particle fluxes in the outer Van Allen radiation belt.
(Evolved Baseline) Only a few particle sensor packages will be deployed. The Burst Detector
Dosimeter (Block) IIR (BDD-IIR) is scheduled to fly on 2 of the first 12 Global Positioning
System (GPS) Block II replenishment series. This instrument measures energetic-particle fluxes,
primarily energetic electrons trapped in the Earth’s radiation belt. BDD-IIR will also measure, to
some extent, the solar energetic particles and galactic cosmic rays. Eight electron channels will
cover the energy spectrum from 77 keV to >5 MeV and eight proton channels will cover 1.3 to
>54 MeV.
1.1.1.3 Defense Support Program (DSP) (DoD)
(Current and Evolved Baseline) Launch and fly-out of the DSP will likely occur before 2010.
Follow-on replacements for the particle sensors are currently not in the baseline of the
replacement program.
1.1.1.4 Compact Environment Anomaly Sensor (CEASE)
(Evolved Baseline) CEASE is a small, lightweight, inexpensive anomaly detector that can fly on
any DoD satellite. CEASE will detect surface charging, deep dielectric charging, and highenergy protons and cosmic rays. Any of these can damage satellite on-board electronics,
sensors, tracking devices, and surfaces. CEASE is a health and status monitor. Data will go
directly to satellite operators and to the 55th SWXS for anomaly assessments. The Concept of
Operations (CONOPS) calls for easy-to-understand read-outs and graphical displays so the
satellite operators can determine quickly if the space environment has caused an anomaly or if
the operators should begin diagnostics. Other potential benefits of CEASE are:
 A reduction in man-hours needed for anomaly resolution
 Extension of operational satellite lifetimes
 Feedback to satellite designers.
A similar instrument is the Small On-Board Environmental Diagnostic Sensor (SOBEDS).
SOBEDS will measure higher-energy particles and vector magnetic fields, and extend CEASE’s
energy range measurements, and provide data for radiation belt specification models.
Given the proposed CONOPS, the estimated total cost for CEASE is $20 million across the
planning horizon with an estimated cost of $200,000 for each instrument. Five satellites will be
launched each year. The planned IOC is 2001. Development is already completed.
1.1.1.5 YOHKOH (International)
(Current Baseline) The Yohkoh satellite is an observatory for studying X-rays and gamma rays from the
Sun. Launched from Kagoshima, Japan, on August 31, 1991, Yohkoh is a project of the Japanese
Institute for Space and Astronautical Sciences. The spacecraft was built in Japan and the observing
instruments have contributions from the United States and from Great Britain.
(Evolved Baseline) GOES with the Solar X-ray Imager (SXI) is the planned operational
replacement for Yohkoh. Follow-on programs with a sensor suite similar to Yohkoh may
provide supplemental observations.
1.1.1.6 Geosynchronous Operational Environmental Satellite (Civil)
(Current Baseline) The National Oceanic and Atmospheric Administration (NOAA) operates
two GOES satellites in geostationary orbit over the United States. GOES provides imagery of
weather phenomena over the continental United States and adjacent oceans. In addition to
sensors that provide such conventional weather information as cloud imagery, each GOES
spacecraft also carries a real-time Space Environment Monitor (SEM).
Each SEM consists of four separate sensor systems. The Energetic Particle Sensor (EPS) and the
High Energy Proton and Alpha Particle Detector (HEPAD) are two instruments that measure the
influx of protons, alpha particles, and electrons over a wide range of energies. The third sensor
is a magnetometer to measure the magnetic field strength and direction at geostationary altitudes.
The fourth sensor is a solar X-Ray Sensor (XRS) that measures the whole-Sun X-ray flux in two
broad energy bands, 1 to 8 angstroms and 0.5 to 4 angstroms.
GOES monitors three main components of space weather at an altitude of 35,000 km: X-rays,
energetic particles, and magnetic field. The GOES X-ray detector provides a sensitive means of
detecting the beginning of solar flares.1 Larger solar flares can cause massive ejections of solar
matter. GOES energetic particle sensors measure this matter, which reaches all points in the
solar system. Solar activity can also cause disturbances in the solar wind. This disturbance can
propagate to Earth and disturb our local magnetic field. The GOES on-board magnetometer
measures fluctuations near the boundary of that field. This magnetometor is used to correlate
with the worldwide system of ground-based magnetometers.
The data are transmitted via direct telemetry to the Space Environment Center (SEC) in Boulder,
Colorado, where they are use in real-time alerts and space weather forecasts. At the end of each
month these data are transferred to the Solar-Terrestrial Physics Division of the National
Geophysical Data Center, an organization known internationally as World Data Center A for
Solar-Terrestrial Physics.
(Evolved Baseline) The newer GOES I through M series of satellites will be operational into the
first decade of the 21st century. GOES L is scheduled for launch in April 2002 and GOES M
April 2000. The next-generation GOES will use both x-ray sensors (XRS) and new extreme
ultraviolet (EUV) monitors. Table 2-4 lists the channels and wavelengths. Table 2-5 shows
projected GOES particle detector instrumentation.
Table 2-4. GOES, XRS, and EUV Channels and Wavelengths
1
sunspots.
XRS/EUV Channel
Short Wavelength (nm)
XRS –A
XRS - B
EUV – A
EUV – B
EUV – C
EUV – D
EUV - E
0.05
0.1
10
25
40
65
119
Long Wavelength (nm)
0.4
0.8
25
40
65
100
124
A solar flare is an explosive event on the Sun’s surface that is fueled by the intense magnetic fields that accompany
Table 2-5. Projected GOES Particle Detector Instrumentation
Particle
Energy Range
Protons (HEPAD)
> 350 MeV
Protons
Protons
Alphas (HEPAD)
0.8 > 500 MeV
80 keV to 800 keV
> 640 MeV/nucleon
Alphas
Electrons
Electrons
3.8 to 400 MeV/nucleon
> 600 keV
30 keV – 600 keV
Energy Channels
3 differential from 350 to about 700 MeV, 1
integral above 700 MeV
7
5
1 differential 640 to about 850 MeV; 1 integral
> 850 MeV
6
3 integral: >0.6, > 2, and > 4 MeV
5
The earth’s upper atmosphere absorbs all x-ray radiation before it reaches the ground. Therefore,
Solar X-ray Imager (SXI) data can only be obtained by space-based instruments. X-ray
information is crucial to space forecasters since x rays are potentially life threatening to
astronauts. X rays are a problem during extra-vehicular activity (EVA) on the space shuttle and,
eventually, on the space station or transatmospheric vehicles. X rays can also affect pilots of
high-altitude aircraft such as the U-2 and
SR-71.
SXI will also provide data on coronal holes. These sources of high-speed solar wind streams
can cause fluctuations in the earth’s magnetic field, increase satellite drag, and interrupt
communications.
The SXI is scheduled to fly on NOAA’s GOES M satellite around 2000 and will provide x-ray
imagery of the Sun’s disk and corona. SXI will also be able to detect x rays from behind the
solar limbs, which can affect the space environment. Japan’s Yohkoh has validated the sensor’s
concept and utility.
The first SXI was built by NASA and funded by the Air Force for $18 million. NOAA will build
the second and third instruments under a memorandum of agreement. DoD will then fund the
fourth and fifth instruments. Estimated cost to build the fourth and fifth SXIs is $20 million for a
total cost of $58 million. NOAA will decide when to launch new GOES satellites on the basis of
constellation health.
1.1.1.7 Advanced Composition Explorer (ACE) (Civil)
(Current Baseline) The Advanced Composition Explorer (ACE) spacecraft uses high-resolution sensors
and monitoring instruments to sample low-energy solar particles and high-energy galactic particles,
energetic ions and electrons, and magnetic field vectors. ACE has a collecting power 10 to 1000 times
greater than past experiments. Located at the L1 libration point, approximately 1/100 of the distance from
the Earth to the Sun, ACE provides near-real-time solar wind information and about a 1-hour advance
warning of impending geomagnetic activity.
For 21 hours each day, ACE sends data (approximately 464 bps) to NOAA operated ground
stations. During the other 3 hours when NASA is getting high rate data through the Deep Space
Network, NOAA gets a copy of the real-time data. NOAA processes all the data (using
algorithms provided by the ACE experimenters) at its Space Weather Operations (SWO) in
Boulder, Colorado. The SWO will issue any warnings of expected geomagnetic activity.
(Evolved Baseline) The specific follow-on program for ACE is to be determined. It is
anticipated that a similar sensor suite at a similar orbit will receive strong support from the
operations and research community.
1.1.1.8 Polar-Orbiting Operational Environmental Satellite (Civil)
(Current Baseline) The NOAA Polar-Orbiting Environmental Satellites (POES) are in a sunsynchronous retrograde polar orbits similar to the DMSP orbit. Like GOES, the NOAA POES
also carry a Space Environment Monitor (SEM) with two instruments, the Total Energy Detector
(TED) and the Medium Energy Proton and Electron Detector (MEPED).
The TED measures electrons and positive ions in the energy range 300 keV to 20 keV. The
positive ions are often assumed to be protons. These data can be used to derive the total energy
flux of incident particles, the total energy input to the hemisphere per unit time, the intensity of
particle precipitation, and the boundaries of the auroral zone.
The MEPED detects electrons, protons, and alpha particles with energies in the range between 30
MeV and 80 MeV. These data provide the capability to map the energetic particle radiation at
Low Earth Orbit (LEO) altitude.
(Evolved Baseline) No significant changes in capabilities are planned for the NOAA POES
sensor suite. Five more satellites are programmed with the last launch scheduled for 2007.
1.1.1.9 National Polar Orbiting Operational Environmental Satellite (Civil)
(Evolved Baseline) DMSP and POES will converge into a single, national polar-orbiting
environmental sensing satellite system. NPOESS is that convergence. This includes not only
single site ground control from the Suitland SOCC, but a single bus with sensors designed to
meet joint DoD and NOAA requirements as determined by the NPOESS Joint Agency
Requirements Group (JARG) and the Senior User’s Advisory Group (SUAG). NPOESS is a triagency effort with DoD, NASA, and NOAA.
NPOESS will consist of a three-satellite constellation at altitudes between 750 and 1200 km and
nominal nodal crossing times of 0530, 0930, and 1330 local sun time. NPOESS will contain
three sensors. A multispectral imager will provide visual and IR imagery at a minimum of seven
bands for clouds, surface, and ocean measurements. A microwave imager/profiler will provide
wind, temperature, and moisture profiles. A space environment sensor will measure parameters
such as electron density profiles, precipitating auroral particles, and geomagnetic field. One of
the satellites in the NPOESS constellation will be a European satellite and will carry U.S.
sensors.
The space environmental sensor suite for NPOESS has not been formulated into a baseline. If
the DMSP 5D-3 SSUSI and SSULI sensors, which measure electron density profiles (EDPs) and
Total Electron Content (TEC), are validated for their operational utility, they are candidates for
the space environmental suite. The current DMSP and POES space environmental sensors that
provide value to user products are also candidates for the converged system.
1.1.1.10 GPS Occultation (Civil)
(Evolved Baseline) GPS occultation involves placing a special-purpose dual frequency GPS
receiver in LEO. From this vantagepoint, the combined orbital motions of the host satellite and
the GPS constellation will allow the receiver to “see” GPS satellites rise and set through the
earth’s limb. Each of these occultations allows measurement of vertical EDPs from 90 km up to
the altitude of the host satellite and vertical temperature and moisture profiles in the lower
atmosphere. About 500 occultations per day are observed from a single platform; however,
highly accurate (1 mm/sec) near-real-time ephemeris is required to remove non-atmospheric
effects from the GPS signal. A ground-based network of GPS receivers may be required to
generate accurate ephemeris as well as to correct additional GPS and receiver clock errors. The
receiver could be deployed on a single satellite or a system with a small number of satellites
(e.g., NPOESS). It could also be deployed on a larger constellation (e.g., Iridium), which would
provide many more occultations but would increase the complexity of the tracking and
processing software needed. The advantage to a larger constellation is global coverage. A
NASA/Jet Propulsion Laboratory (JPL) proposal calls for using 12 microsatellites (weight under
50 pounds each) at a total cost of $12 million for such a constellation.
1.1.1.11 Communications/Navigation Outage Forecasting System (C/NOFS ) (Civil)
(Evolved Baseline) C/NOFS will fly seven proven sensors on-board a satellite with a 12-degree
inclination at 600-700 km. These sensors will detect ionospheric scintillation, which causes a
degradation of satellite communications signals (primarily UHF) and navigation signals.
C/NOFS will also detect conditions that could lead to scintillation and thus provide a forecast of
potential SATCOM outage times and affected frequencies along with potential GPS signal
degradation. One satellite will provide data to users once every 110 minutes, which is usually
enough to detect scintillation or conditions leading to scintillation. C/NOFS can also provide
data to the 55th Space Weather Squadron (55 SWS) for use in scintillation forecasts. These data
will greatly improve current scintillation notifications and forecasts as well as increase the
refresh rate from approximately 6 hours to around 1½ hours. AFSPC/SCZ has a validated
requirement for C/NOFS type data.
With an estimated IOC of 2002, total costs for C/NOFS are $85 million through the planning
horizon. This includes $6 million for each satellite, $15 million per launch on a Pegasus or
Pegasus XL, and $1 million annual operating costs. This does not include the STP
demonstration flight.
1.1.1.12 IMAGE (Civil)
(Evolved Baseline) IMAGE is a mission to study the global response of the Earth's
magnetosphere to changes in the solar wind. IMAGE will identify the dominant mechanisms for
injecting plasma into the magnetosphere on substorm and magnetic storm time scales. It will
also determine the directly driven response of the magnetosphere to solar wind changes. Finally,
it will discover how and where magnetospheric plasmas are energized, transported, and
subsequently lost during substorms and magnetic storms.
To fulfill its science goals, IMAGE will use neutral atom, ultraviolet, and radio imaging
techniques. Specific imagers include the Neutral Atom Imagers (NAI), Low-Energy Neutral
Atom (LENA) imager, Medium-Energy Neutral Atom (MENA) imager, High-Energy Neutral
Atom (HENA) imager, Extreme Ultraviolet Imager (EUV), Far Ultraviolet Imager (FUV), and
Radio Plasma Imaging (RPI).
The IMAGE mission has a completely open data policy with no periods of proprietary data
rights. Level 0 data will be delivered to the National Space Science Data Center (NSSDC) for
long-term archiving and distribution along with a series of browse and other calibrated data
products. The NSSDC will immediately place these IMAGE data on-line in the NASA Data
Archive and Distribution Service (NDADS) system for rapid access by the space science
community.
The projected launch is date is January 2000. The Orbit will be a 1,000-km by seven-earth radii
altitude polar orbit. Mission duration is 2 years.
1.1.1.13 Solar Terrestrial Relations Observatory (STEREO) Mission (Civil)
(Evolved Baseline) The STEREO mission is to perform solar activity imaging by two or more
spacecraft at large angular separations from Earth. One spacecraft orbit would be 20° to 30° out
of the ecliptic plane. STEREO requires supporting observations from (near) Earth. This mission
will provide real-time event alerts for forecasters. The science objectives are:
Understand the origin and consequences of coronal mass ejections (CMEs)
Establish the magnetic field evolution that results in solar eruptions
Improve space weather forecast capability
Determine the 3D structure of disturbed interplanetary magnetic fields
Discover the mechanisms and sites of energetic particle acceleration
Determine whether CMEs control the evolution of the corona
Probe the solar dynamo through study of cyclic phenomena in the corona and interplanetary space.
STEREO will image the chromosphere, corona, and interplanetary plasmas and photospheric
magnetic fields from several perspectives simultaneously and measure plasmas, magnetic fields,
and energetic particles in situ.
1.1.1.14 Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC)
(Civil)
(Evolved Baseline) COSMIC is a follow-on program to an experimental satellite called GPS/MET. This
experiment used the Global Positioning System to derive important weather and climate research
parameters. Included in the measurements is the electron density of the ionosphere. COSMIC will
advance this research by testing the ability of a constellation of approximately eight “GPS/MET microsatellites” to measure electron densities. A global data collection network and operations center will
process COSMIC space and ground observations and deliver products to users for operational impact
studies. The COSMIC constellation will be launched early in the year 2001 and will operate for 2 years.
It is being developed by the Taiwan’s National Space Program Office (NSPO) in cooperation NASA JPL
and several universities.
1.1.2 Ground-Based Sensors
1.1.2.1 Solar Optical Observing Network (DoD)
(Current Baseline) The four Solar Observing Optical Network (SOON) observatories are part of
the Solar Electro Optical Network (SEON). The SEON consists of six sites distributed around
the world. These sites monitor the Sun continuously in visible light and radio wavelengths.
Table 2-6 lists the SOON observatories.
Table 2-6. SOON Observatories
SOON Observatories
Holloman AFB, New Mexico
Ramey, Puerto Rico
San Vito, Italy
Learmonth, Australia
Location
32N106W
18N67W
41N18E
21S115E
Each SOON telescope (AN/FMQ-7) uses a 10-inch objective lens and a series of beam splitters,
scanner mirrors, and other lenses to supply photographic, video, and visual observing subsystems
with a stabilized image of the Sun.
Visual observations are available on a white light projection board and through eyepieces in two
light paths. The white light projection board displays sunspots located in the photosphere. The
upper light path isolates the Hydrogen alpha (H-alpha) wavelength to observe the features of the
chromosphere. The lower light path is used in conjunction with a magnetograph to map the
magnetic field of active regions on the Sun. A mini-computer operates the telescope, analyzes
solar observations, and displays the selected output on television monitors.
(Evolved Baseline) An Improved SOON (ISOON) telescope will replace the current SOON
optical telescope. ISOON will be based on a fully tunable narrow-band filter and CCD detector.
This telescope will feature autonomous, rapid-cadence solar imaging and remote operation at
four existing sites (Holloman, Learmonth, San Vito, and Ramey). ISOON will transmit solar
images in near-real time to central facilities at Falcon AFB and Boulder, Colorado. ISOON data
products will include full-disk H-alpha, continuum, and line-of-sight magnetic field images (all
on 1-arcsec pixels). High-resolution images (limited field, 0.3-arcsec pixels) will be available
via a future upgrade in the secondary optics. ISOON will also be capable of acquiring vector
magnetic field images via a software upgrade to be added at a future time. ISOON data
derivatives include intensity histograms, flare area, brightness, location, start, maximum, end,
heliographic coordinate overlay, movie playbacks and pseudocolor graphical displays, and
cartesian coordinate transformation and display.
1.1.2.2 Radio Solar Telescope Network (DoD)
(Current Baseline) The Radio Solar Telescope Network (RSTN) is a network of systems that
detect, quantify, and report on solar radio events. Each RSTN (AN/FRR-95) observatory uses
three dish antennas to detect solar radio noise at eight discrete frequencies. Radio Interference
Monitoring Sets (RIMS) measure solar radio energy at eight fixed frequencies (245, 410, 610,
1415, 2695, 4995, 8800, and 15400 MHz). These data are then screened for patterns indicating
solar activity. RSTN was the Swept Frequency Interferometric Radiometer (SFIR) as the
primary system to detect and specify solar radio events. Specialized radio receivers sweep
through a range of frequencies (25 MHz – 75 MHz) and identify events, including solar location,
strength, and radio frequency. The Solar Radio Burst Locator (SRBL), a secondary system, is
particularly useful in identifying short-duration solar radio events that may be missed by SFIR.
Four RSTN observatories are also part of the SEON (see Table 2-7).
Table 2-7. RSTN Observatories
RSTN Observatories
Sagamore Hill, Massachusetts
San Vito, Italy
Learmonth, Australia
Palehua, Hawaii
Location
42N70W
41N118E
21S115E
21N158W
Both standard reports and alerts are produced when appropriate. Data are processed on-site at
each network location. The Automated Weather Network (AWN) forwards summaries and
alerts in plain language and encoded formats. Processed data is transmitted continuously, within
1 minute of observation, at 2.4Kbps, except Learmonth, which is at 1.2Kbps. Sites identify solar
regions with high levels of activity. This identification provides continuity between sites as an
individual site’s solar visibility rises and fades.
(Evolved Baseline) A Solar Radiospectrograph (SRS) will replace the current Swept Frequency
Interferometric Radiometer (SFIR). The current SFIR is limited in solar patrol range (25–75
MHz), is difficult to maintain, and has difficulty in accurately measuring Sweep Activity. The
SRS more accurately characterizes Types II and IV radio bursts and provides a capability of
remote operation and data transfer. The SRS is a combination of the SFIR (antenna, filters
amplifier) and Culgoora Radiospectrograph (data acquisition and display software and
hardware). The system will use software code already developed for Culgoora’s radiometer.
The conversion of the existing SFIR to a Swept Frequency Radiometer will allow account event
shock speed measurement and extend the frequency range to 25–180 MHz where more than 99
percent of sweep activity occurs.
A Solar Radio Burst Locator (SRBL) telescope will replace the current RSTN’s fixed frequency
RIMS telescopes with a system sensitive to a wider, continuous range of radio frequencies and
with some radio burst location capability. The present RSTN only monitors eight discrete
frequencies and cannot determine where on the Sun a radio burst originated. The SRBL will
permit direct observation of any frequency requested by a customer and will provide burst
location information for those bursts between 2 and 18 GHz and with intensities of 500 SFUs or
greater. This location capability will supplement optical observations during periods of
cloudiness or precipitation. The SRBL will also replace the current 3-antenna discrete frequency
RSTN (i.e., RIMS) with a single 6-foot antenna; and the current 11 racks of antenna controls and
radiometers with a dual PC workstation. The SRBL will provide considerably more automation
in the radio observing process, and will permit remote operation and data analysis at the SEOC.
1.1.2.3 Digital Ionospheric Sounding System (DoD)
(Current Baseline) Vertical incidence ionospheric sounders (ionosondes) measure the relevant
features of the bottomside of the ionosphere. A few analog ionosondes remain in operation and
still provide reliable and useful ionospheric parameters. Most ionosondes now take advantage of
state-of-the-art microprocessors, integrated circuits, and large-capacity memory storage devices.
The early analog ionosondes, designed and built in the 1950s, generate a Polaroid camera
photograph of an ionogram displayed on an oscilloscope screen. An experienced analyst
interprets the ionogram to determine the critical frequencies of the various layers of the
ionosphere. Nicosia, Cyprus, located at 35N and 33E, is the one remaining station that routinely
provides observations.
The Digital Ionospheric Sounding System (DISS) (AN/FMQ-12) takes advantage of state-of-theart integrated circuit technology to provide real-time ionospheric observations. It measured and
distributes the data automatically, with no manual intervention. Table 2-8 lists the sites.
Table 2-8. DISS Ionosonde Sites
DISS Ionosondes
King Salmon, Alaska
College, Alaska
Vandenberg AFB, California
Dyess AFB, Texas
Eglin AFB, Florida
Wallops Island, Virginia
Ramey, Puerto Rico
Hamilton, Bermuda
Argentia, Canada
Goose Bay, Canada
Narssarssuaq, Greenland
Sondrestrom, Greenland
Qaanaaq (Thule), Greenland
Learmonth, Australia
Location
58N157W
64N147W
34N120W
34N120W
31N86W
37N75W
18N67W
32N65W
48N53W
53N60W
61N45W
67N51W
78N69W
21S115E
(Evolved Baseline) No significant improvement or expansion of the Digital Ionospheric
Sounding System (AN/FMQ-12) is programmed through 2010.
1.1.2.4 Ionospheric Measuring System (IMS) (DoD)
(Current Baseline) The Ionospheric Measuring System (IMS) was formerly known as the
Transionospheric Sensing System (TISS). IMS measures Total Electron Content (TEC) by
exploiting two frequencies (1575.42 MHz and 1227.60 MHz) of the Navstar Global Positioning
System (GPS) Precise Positioning Service (PPS). Table 2-9 lists the IMS sites.
Table 2-9. IMS Ground Stations
IMS Ground Stations
Eareckson AS, Shemya, Alaska
Thule AB, Greenland
Otis ANG, Massachusetts
RAF Fylingdales, UK
Diego Garcia, BIOT
Location
53N174E
76N68W
42N70W
54N1W
7S73E
(Evolved Baseline) The Ionospheric Measuring System instruments are to be phased out at the
start of FY04.
1.1.2.5 Neutron Monitor (DoD)
(Current Baseline) The Neutron Monitor, located at Thule, Greenland, is used for ground-based
detection of secondary neutrons produced during collisions between high energy “cosmic rays”
and molecules or atoms in the Earth’s atmosphere. It indirectly measures the cosmic ray flux
encountered by the Earth, whether from outside the solar system (galactic cosmic rays) or the
most intense of solar flares (solar cosmic rays). Sudden increases in the secondary neutron
fluxes known as Ground Level Events (GLE) are important as an indicator that a very energetic
solar flare has occurred, and a Polar Cap Absorption (PCA) event is almost certain to follow.
(Evolved Baseline) No replacement for the Neutron Monitor has been programmed.
1.1.2.6 Relative Ionospheric Opacity Meter (Riometer) (DoD)
(Current Baseline) The Riometer, located at Thule, Greenland, records the strength of High
Frequency (HF) cosmic radio noise2 received at the Earth’s surface. A decrease in power
represents an increase in ionospheric opacity or absorption. Riometers can detect ionospheric
disturbances that may cause Short Wave Fades (SWFs), Auroral Zone Absorption (AZA), and
Polar Cap Absorption (PCA) events. The instrument at Thule is currently the only instrument for
detecting and monitoring PCAs.
(Evolved Baseline) No replacement of the Riometer has been programmed.
1.1.2.7 Scintillation Network Decision Aid (SCINDA) (DoD)
(Evolved Baseline) Scintillation Network Decision Aid is an ongoing PL/GPI effort to provide
real-time specification and short-term forecasts of satellite communication outages in the
equatorial region. Real-time data from remote, ground-based scintillation receivers are used to
derive an empirical scintillation model. The model generates three-dimensional displays of
scintillation structures and simplified outage maps for communications and navigation users.
SCINDA can be used in conjunction with C/NOFS and provide a portable scintillation capability
to deployed forces. SCINDA will combine with C/NOFS to improve scintillation notification
and forecast accuracy, timeliness, and refresh rate.
Because much of the R&D and validation testing has been done, SCINDA is a relatively lowcost solution. With a 1999 IOC, cost estimate is $7 million across the planning horizon for 14
instruments at $200,000 each plus O&M.
1.1.2.8 Canadian Radio Observatory (International)
(Current Baseline) The Canadian Radio Observatory, also known as the Dominion Astrophysical Radio
Observatory (DARO), is located at Penticton, British Columbia, Canada. This site is the primary source
for measurement of solar radio energy at the 10.7-cm wavelength (2800 MHz). This index, F10.7, is a key
measure of solar activity. The variation of the 10.7-cm radio flux is closely associated with enhanced
thermal radiation from solar active regions, and thus the overall level of solar activity. Many high
frequency (HF) communications customers use this index directly. It is also a key input parameter in
many ionospheric and orbital prediction models.
(Evolved Baseline) No significant improvement of the Canadian Radio Observatory, also known
as the Dominion Astrophysical Radio Observatory (DARO), is programmed through 2010.
1.1.2.9 Australian Observatory (International)
(Current Baseline) The Culgoora Solar Observatory is located 25 km west of the town of Narrabri, in
northwest New South Wales. The observatory conducts continuous optical and radio observations of the
Sun throughout the year. Observing instrumentation includes a 12-cm solar telescope fitted with a
hydrogen-alpha filter, used to observe solar flares and other phenomena. The observatory also has a 30cm heliostat, used to observe sunspot evolution. A solar radio spectrograph, which sweeps through a
frequency range of 18 to 1800 MHz every 3 seconds, monitors solar radio bursts. The observatory
transmits regular reports and forecasts of solar activity to the Australian Space Forecast Center in Sydney
and disseminates these reports to similar organizations internationally. The observatory reports
particularly significant solar outbursts to a wide range of interested parties around the world within
minutes of the outburst.
(Evolved Baseline) No significant improvement of the Australian Solar Observatory is
programmed through 2010.
2
Radiowaves emanating from extraterrestrial sources.
1.1.2.10 Australian Ionospheric Network (International)
(Current Baseline) The Australian Ionospheric Network, also known as the Southern Hemisphere
Ionospheric Network (SHIN), provides ionospheric sounder data via NOAA/SEC. These ionospheric
sounders provide vertical incidence ionospheric measurements routinely. Table 2-10 lists SHIN sites.
Table 2-10. SHIN Sites
Southern Hemisphere Ionospheric Network
Camden, Australia
Christchurch, New Zealand
Darwin, Australia
Hobart, Australia
Townsville, Australia
Location
S34 E151
S43 E171
S12 E131
S42 E147
S19 E147
(Evolved Baseline) No significant improvement of the Australian Ionospheric Network, also
known as the Southern Hemisphere Ionospheric Network (SHIN), is programmed through 2010.
1.1.2.11 National Solar Observatories (Civil)
(Current Baseline) The National Solar Observatory (NSO) operates two major observatory
sites. On Sacramento Peak in southern New Mexico, major telescopes include the Vacuum
Tower Telescope, the John W. Evans Solar Facility, and the Hilltop Dome. Operations are a
cooperative undertaking of NSO and the Air Force Phillips Laboratory. When fed with the John
W. Evans Solar Facility 40cm Coronagraph, the Fisher-Smartt Emission Line Coronal
Photometer (ELCP) photoelectrically records the solar corona. The output of the ELCP is sensed
by a photomultiplier, digitized, and recorded every 3 degrees of latitude. The ELCP obtains
obsolute intensities, in millionths of the brightness of the center of the disk, at each wavelength.
NSO joins 15 days of data and projects the data onto a sphere to produce pseudo-full-disk maps.
The most recent scan is on the left of the map, and the data on the central meridian are from 7
days before the date of the map. Data are incremented from the central meridian at 12.857
degrees per day. West-limb maps, which show the far side of the Sun on the day they are
produced, have an effective date of 2 weeks into the future, so that they may be compared with
East-limb maps of the same date. Maps are normally available for each Monday through
Friday, excluding holidays.
On Kitt Peak, outside of Tucson, Arizona, NSO operates the McMath-Pierce Solar Facility and
the vacuum solar telescope. Synoptic observations at the vacuum telescope, jointly supported by
NSO, NASA, and NOAA, have produced a 20-year record of solar magnetic activity. This
record is now partially available through ftp and the World Wide Web. The McMath-Pierce
Facility houses the world's three largest solar telescopes.
Mt. Wilson in California sends a daily sunspot magnetic classification fax to the 55 SWXS and
NOAA/SEC. The Mt. Wilson Institute, which includes the Hale Solar Observatory, is not part of
the NSO, but is a non-profit organization.
(Evolved Baseline) No significant improvement of the National Solar Observatory is
programmed through 2010.
1.1.2.12 Jet Propulsion Laboratory Total Electron Content Monitors (Civil)
(Current Baseline) The Jet Propulsion Laboratory (JPL) provides ionospheric data from more than 25
passive receivers operating worldwide. These JPL sites are part of a worldwide network of more than 100
receivers. The JPL network uses GPS signals to measure total electron content (TEC). Table 2-11 lists
the passive receiver sites.
Table 2-11. JPL Sites
Station Name
Auckland, New Zealand
College, Alaska
Ensenada, Mexico
Fredericksburg, MD
Goldstone, CA
Guam
JPL Mesa, CA
Kokee, Kauai, HI
Mauna Kea, HI
McDonald, TX
Mcmurdo, Antarctica
North Liberty, Iowa
Nyalesund2, Norway
Oat Mountain, CA
Pasadena, CA
Pie Town, New Mexico
Potsdam, Germany
Quincy, CA
Santiago, Chile
St Croix, Virgin Islands
Tidbinbilla, Australia
Tromso2, Norway
Usuda, Japan
Westlake, CA
Wettzell, Germany
Latitude
Longitude
-36.60
64.90
31.87
38.00
35.42
13.59
34.20
22.13
19.80
30.68
-77.84
41.77
78.93
34.35
34.14
34.30
52.38
39.38
-33.15
17.76
-35.40
69.66
36.13
34.16
49.14
174.83
212.20
243.33
283.00
243.11
144.87
241.83
200.34
204.54
255.99
166.67
268.43
11.86
241.40
241.87
251.88
13.07
239.06
289.33
295.42
148.98
18.94
138.36
241.17
12.88
(Evolved Baseline) No significant improvement or expansion of the JPL TEC Monitors is
programmed through 2010. Some new JPL TEC sites may be substituted or added to satisfy a
particular customer need.
1.1.2.13 U. S. Geological Survey Magnetometers (Civil)
(Current Baseline) The United States Geological Survey (USGS) operates a network of groundbased magnetometers. Several of these magnetometers provide the data used at 55 SWXS to
compute the level of geomagnetic activity in real time. The 55 SWXS calculates the planetary
geomagnetic indices KP and AP. They base these indices on reports from the magnetometers
located in the United States and Canada, as listed in Table 2-12. The stations located in Canada
are Canadian owned. The USGS also owns and operates other real-time reporting
magnetometers. Some of these additional sites (also listed in Table 2-10) are monitored for
geomagnetic activity. Geomagnetic variations are reported, calculated, and transmitted
routinely.
The USGS-operated sensors forward data every 12-minutes to a GOES spacecraft. GOES
retransmits the data to Wallops Island, Virginia, then to the NOAA Data Collection System at
Camp Springs, Maryland, then to the SESC in Boulder, Colorado, and finally to the 55 SWXS.
Table 2-12. USGS Magnetometers
Location
USGS-Operated Magnetometers
Sitka, Alaska
Meanook, Canada
Glenlea, Canada
Ottawa, Canada
St. Johns, Newfoundland, Canada
Newport, Washington
Fresno, California
Boulder, Colorado
Coordinates
57N135W
55N113W
50N97W
45N76W
47N54W
42N117W
37N120W
40N105W
Canadian-Owned
Canadian-Owned
Canadian-Owned
Canadian-Owned
Canadian and USGS-Operated
Magnetometers
Fredericksburg, Virginia
Resolute Bay, Canada
Baker Lake, Canada
Churchill, Canada
Cambridge Bay, Canada
Yellow Knife, Canada
Post de la Beleine, Canada
College, Alaska
Anchorage, Alaska
Victoria, Canada
Tucson, Arizona
Del Rio, Texas
San Juan, PR
Honolulu, Hawaii
38N77W
N74W 94
N64W 96
N58W 94
N60W105
N62W114
N55W 77
N64W147
N61W150
N49W123
N32W110
N30W101
N18W 66
N21W158
(Evolved Baseline) No significant improvement of the Magnetometers is programmed through
2010. Some new USGS sites may be substituted or added to satisfy a particular customer need.
1.1.3 Data Processing Centers
1.1.3.1 United States Air Force Space Environment Operations Center
1.1.3.2 National Oceanic and Atmospheric Administration Space Environment Center
1.1.3.3 Archival Center
Solar and geophysical data are archived by the NESDIS/National Geophysical Data Center
(NGDC) in Boulder, Colorado. This agency also fulfills the functions of a World Data Center
(WDC) in accordance with the International Data Exchange guidelines and through various ad
hoc arrangements with other WDCs and sources of data. Data include solar images, sunspots,
energetic particles, cosmic rays, geomagnetic measurements, ionospheric soundings, auroral
images, auroral particles, and activity indices. Data less than 30 days old may be available at the
SEC. NGDC holds over 163 Gigabytes of digital data from about 340 worldwide observatories
and stations and many miles of microfilm. The NGDC mission includes data rescue (maintain
archives for 204 closed solar observatories, 79 closed cosmic ray neutron monitor stations, and
many closed geomagnetic and ionospheric stations).
NGDC collects, checks, and disseminates space weather data via the Geophysical On Line Data
(GOLD) system on the worldwide web (http://www.ngdc.noaa.gov, gopher.ngdc.noaa.gov, ftp
anonymous, ftp.ngdc.noaa.gov) and bulletin board access. New online search capabilities for
space weather plots, Space Physics Interactive Data Resource (SPIDR), now provides
geomagnetic, aurora, and ionospheric data. Solar data will be included in SPIDR in the near
future. A monthly publication, Solar-Geophysical Data (SGD), is available by subscription.
This publication includes historical solar activity data compiled from worldwide observatories
and related satellite and ground-based geomagnetic and cosmic ray indices that document the
effects on the Earth environment. Popular solar and geomagnetic indices are distributed quickly
via the monthly Solar Indices Bulletin and the Geomagnetic Indices Bulletin. Large digital space
weather databases are available via CD-ROM or other media as requested.