IAU Meeting 2006 Aug 21 NJIT Center for Solar Terrestrial Research 3 / 22
FASR Instrument (Antennas)
Three arrays, 4.2 km baselinesThree arrays, 4.2 km baselines
Array Designation
Number of Antennas
Frequency Range
Antenna Size
FASR-A High Frequency Array
~1002-20 GHz
2-30 (goal)2 m
FASR-BLow Frequency Array
~60 0.2-3 GHz 6 m
FASR-CLog-Periodic Dipole Array
~4050-300 MHz
20-300 (goal)Log-
dipole
IAU Meeting 2006 Aug 21 NJIT Center for Solar Terrestrial Research 5 / 22
FASR Instrument (Receivers)
Broadband RF transmission, Digital FX CorrelatorBroadband RF transmission, Digital FX Correlator
Quantity Spec
Frequency Resolution0.01% (internal)
1-3% (output)
Time Resolution100 ms (FASR-B/C)
1 s (FASR-A)
Polarization Stokes IV (QU)
Instantaneous Bandwidth ~1 GHz
IAU Meeting 2006 Aug 21 NJIT Center for Solar Terrestrial Research 6 / 22
FASR Science GoalsFASR Science GoalsDesigned to be the world’s premier solar radio Designed to be the world’s premier solar radio facility for at least two decades after completion.facility for at least two decades after completion.
Full capability to address a broad range of solar Full capability to address a broad range of solar science:science:
1.1. Nature and evolution of coronal magnetic fieldsNature and evolution of coronal magnetic fields
2.2. Physics of flaresPhysics of flares
3.3. Drivers of space weatherDrivers of space weather
4.4. Physics of the quiet solar atmospherePhysics of the quiet solar atmosphere
Designed to be the world’s premier solar radio Designed to be the world’s premier solar radio facility for at least two decades after completion.facility for at least two decades after completion.
Full capability to address a broad range of solar Full capability to address a broad range of solar science:science:
1.1. Nature and evolution of coronal magnetic fieldsNature and evolution of coronal magnetic fields
2.2. Physics of flaresPhysics of flares
3.3. Drivers of space weatherDrivers of space weather
4.4. Physics of the quiet solar atmospherePhysics of the quiet solar atmosphere
IAU Meeting 2006 Aug 21 NJIT Center for Solar Terrestrial Research 7 / 22
Objectives to Measurements
Key Science Objectives
Science GoalsMeasurement
GoalsObservables
Emission Mechanism
Measurement Requirements1
D Tb (K) (s)
Objective 1: The nature and evolution of coronal magnetic Fields
A: Coronal Magneto-graphy of active regions
Strong magneticfields (>150 G)
a: Active region
multi- Tb maps Gyroresonance 1-18 1% 3000 1000 1800
B: Coronal Magneto-graphy of the quietSun
LOS magnetic Fields
b: Full-Sun
multi- Tb maps Free-free 1-20 1% 1000 300 1800
C: Magnetic connectivity of the corona to the heliosphere
Coronal field and topology
1a, 1b See above - - - - -
c: Active region multi- poln Maps
Mode-coupling depolarization surface
1-20 1% 1000 1000 1800
d: dm- and m- type III bursts
Plasma 0.03-3 1% 1000 105 0.01
IAU Meeting 2006 Aug 21 NJIT Center for Solar Terrestrial Research 8 / 22
Magnetic Field Spectral DiagnosticsMagnetic Field Spectral Diagnostics
• Model spectra along 2 Model spectra along 2 lines of sight: lines of sight: aa) negative polarity ) negative polarity sunspot, sunspot, bb) positive ) positive polarity sunspot.polarity sunspot.
• The coronal The coronal temperature and the temperature and the magnetic field strength magnetic field strength can be read directly can be read directly from the spectra.from the spectra.
Model from Mok et al., 2004;
Simulation from Gary et al. 2004
IAU Meeting 2006 Aug 21 NJIT Center for Solar Terrestrial Research 9 / 22
2D Magnetogram2D Magnetogram• BB map deduced map deduced
from 1—24 GHz from 1—24 GHz spectra (spectra (bb) match ) match the model (the model (aa) very ) very well, everywhere well, everywhere in the region. (in the region. (cc) ) is a comparison is a comparison along a line along a line through the center through the center of the region.of the region.
• The fit only works The fit only works down to 119 G down to 119 G (corresponding to (corresponding to ff = 3 = 3 ffBB = 1 GHz) = 1 GHz)
from Gary et al. 2004
IAU Meeting 2006 Aug 21 NJIT Center for Solar Terrestrial Research 10 / 22
Objectives to Measurements
Key Science Objectives
Science GoalsMeasurement
GoalsObservables
Emission Mechanism
Measurement Requirements1
D Tb (K) (s)
Objective 1: The nature and evolution of coronal magnetic Fields
A: Coronal Magneto-graphy of active regions
Strong magneticfields (>150 G)
a: Active region
multi- Tb maps Gyroresonance 1-18 1% 3000 1000 1800
B: Coronal Magneto-graphy of the quietSun
LOS magnetic Fields
b: Full-Sun
multi- Tb maps Free-free 1-20 1% 1000 300 1800
C: Magnetic connectivity of the corona to the heliosphere
Coronal field and topology
1a, 1b See above - - - - -
c: Active region multi- poln Maps
Mode-coupling depolarization surface
1-20 1% 1000 1000 1800
d: dm- and m- type III bursts
Plasma 0.03-3 1% 1000 105 0.01
IAU Meeting 2006 Aug 21 NJIT Center for Solar Terrestrial Research 11 / 22
Bl from Free-Free Emission• With sufficient With sufficient
polarization polarization sensitivity, sensitivity, BBll
can be deduced can be deduced everywhere everywhere down to ~ 20 G down to ~ 20 G using:using:
where where nn is the is the spectral indexspectral index
from Gelfreikh, 2004—Ch. 6from Gary & Hurford, 2004—Chapter 4
IAU Meeting 2006 Aug 21 NJIT Center for Solar Terrestrial Research 12 / 22
Objectives to Measurements
Key Science Objectives
Science GoalsMeasurement
GoalsObservables
Emission Mechanism
Measurement Requirements1
D Tb (K) (s)
Objective 1: The nature and evolution of coronal magnetic Fields
A: Coronal Magneto-graphy of active regions
Strong magneticfields (>150 G)
a: Active region
multi- Tb maps Gyroresonance 1-18 1% 3000 1000 1800
B: Coronal Magneto-graphy of the quietSun
LOS magnetic Fields
b: Full-Sun
multi- Tb maps Free-free 1-20 1% 1000 300 1800
C: Magnetic connectivity of the corona to the heliosphere
Coronal field and topology
1a, 1b See above - - - - -
c: Active region multi- poln Maps
Mode-coupling depolarization surface
1-20 1% 1000 1000 1800
d: dm- and m- type III bursts
Plasma 0.03-3 1% 1000 105 0.01
IAU Meeting 2006 Aug 21 NJIT Center for Solar Terrestrial Research 13 / 22
Magnetic Topology from QT Layer• Upper panels show
radio “depolarization line” (DL) at a single frequency due to mode-conversion at a quasi-transverse (QT) layer, vs. photospheric neutral line (NL).
• Using FASR’s many frequencies, a QT surface can be mapped in projection. The surface changes greatly with viewing angle.
from Ryabov, 2004—Chapter 7
IAU Meeting 2006 Aug 21 NJIT Center for Solar Terrestrial Research 14 / 22
Prototyping Efforts
• Green Bank Solar Radio Burst Spectrometer (feed development)
• FASR Subsystem Testbed--FST (design platform, RFI mitigation, solar observations)
• French Activities (RFI mitigation, FPGA technology)
IAU Meeting 2006 Aug 21 NJIT Center for Solar Terrestrial Research 15 / 22
Green Bank Solar Radio Burst Spectrometer
Feed Development• 20-70 MHz system
using “fat dipole”• 50-250 MHz feed on
45-foot telescope • 200-1070 MHz on 45-
foot telescopehttp://www.astro.umd.edu/~white/gb/http://www.astro.umd.edu/~white/gb/
IAU Meeting 2006 Aug 21 NJIT Center for Solar Terrestrial Research 16 / 22
FST System• HardwareHardware
1-9 GHz RF 500 MHz instantaneous BW Record full-res time-domain
signal, off-line processing
• Block DiagramBlock Diagram
ImageRejection
D-C Modules &Variable LO
Chassis
AcqirisDigitizer
Control/RecordingComputer
CAN Bus D-C Mod Ctrl
FrontEnd Box
BlockDown-converter
Chassis
FrontEnd Box
FrontEnd Box
OVSAAnt 5RF
OVSAAnt 6RF
OVSAAnt 7RF
FO Rcvr &AmplifierChassis
Parallel Port LO Ctrl
DIO Switch Ctrl
Fiber
Dig
itize
r C
trl
IAU Meeting 2006 Aug 21 NJIT Center for Solar Terrestrial Research 17 / 22
Results (RFI)
• 10000-pt spectra (10000-pt spectra (dd = = 50 kHz), 10 50 kHz), 10 s time s time resolution sample of resolution sample of local interference local interference signalsignal
• Goal is to identify and Goal is to identify and excise interference in excise interference in real timereal time
• Hiro Kawakubo and Hiro Kawakubo and Chris Ruf (U Mich) are Chris Ruf (U Mich) are studying use of studying use of kurtosis statistickurtosis statistic Time
Frequency
IAU Meeting 2006 Aug 21 NJIT Center for Solar Terrestrial Research 18 / 22
Results (Satellites)• First Fringes (GPS satellite, L1 First Fringes (GPS satellite, L1
signal, 1575.42 MHz)signal, 1575.42 MHz)
IAU Meeting 2006 Aug 21 NJIT Center for Solar Terrestrial Research 19 / 22
Results (Satellites)• Geostationary Satellite Geostationary Satellite
Galaxy 10RGalaxy 10R• Can phase information Can phase information
be used for calibration?be used for calibration?• Overlapping channels Overlapping channels
are linearly (H and V) are linearly (H and V) polarized, which offers polarized, which offers possibility of linear possibility of linear polarization calibrationpolarization calibration
IAU Meeting 2006 Aug 21 NJIT Center for Solar Terrestrial Research 20 / 22
20 s of FST Amplitude Data20 s of FST Amplitude Data
B5.1 Flare (2006 Apr 05)
Results (Solar)
IAU Meeting 2006 Aug 21 NJIT Center for Solar Terrestrial Research 21 / 22
FST Amplitude & Corrected Phase
Burst locations essentially identical from burst to burst, and from one
polarization to another
Burst locations essentially identical from burst to burst, and from one
polarization to another
IAU Meeting 2006 Aug 21 NJIT Center for Solar Terrestrial Research 22 / 22
Status and ConclusionStatus and Conclusion• FASR is being designed to address an FASR is being designed to address an
extremely rich range of solar science, utilizing extremely rich range of solar science, utilizing state-of-the-art technology. state-of-the-art technology.
• Some aspects of the instrument are currently Some aspects of the instrument are currently being prototyped.being prototyped.
• Most recent proposal received highest Most recent proposal received highest recommendation, but funding has been recommendation, but funding has been reduced and delayed by funding agency.reduced and delayed by funding agency.
• Next step is to construct a 10-element Next step is to construct a 10-element prototype array, to be ready by 2010. Proposal prototype array, to be ready by 2010. Proposal to be submitted as soon as possible.to be submitted as soon as possible.
• FASR is being designed to address an FASR is being designed to address an extremely rich range of solar science, utilizing extremely rich range of solar science, utilizing state-of-the-art technology. state-of-the-art technology.
• Some aspects of the instrument are currently Some aspects of the instrument are currently being prototyped.being prototyped.
• Most recent proposal received highest Most recent proposal received highest recommendation, but funding has been recommendation, but funding has been reduced and delayed by funding agency.reduced and delayed by funding agency.
• Next step is to construct a 10-element Next step is to construct a 10-element prototype array, to be ready by 2010. Proposal prototype array, to be ready by 2010. Proposal to be submitted as soon as possible.to be submitted as soon as possible.
IAU Meeting 2006 Aug 21 NJIT Center for Solar Terrestrial Research 24 / 22
FASR EndorsementsFASR Endorsements2001 Astronomy & Astrophysics Survey Committee
• Ranked as one of 17 priority projects for this decade
• one of 3 solar projects, with ATST and SDO
2003 Solar and Space Physics Survey Committee
• Ranked as top priority in small (<$150 M) projects
2002-2004: Design Study (NSF/ATI)
• 3 workshops for community input
• Science consensus, hardware and software design options, and development of management plan.
2004-2006: FASR Long-Lead Prototyping Proposal (NSF/ATI)
2001 Astronomy & Astrophysics Survey Committee
• Ranked as one of 17 priority projects for this decade
• one of 3 solar projects, with ATST and SDO
2003 Solar and Space Physics Survey Committee
• Ranked as top priority in small (<$150 M) projects
2002-2004: Design Study (NSF/ATI)
• 3 workshops for community input
• Science consensus, hardware and software design options, and development of management plan.
2004-2006: FASR Long-Lead Prototyping Proposal (NSF/ATI)
IAU Meeting 2006 Aug 21 NJIT Center for Solar Terrestrial Research 25 / 22
FASR Signal Path
Correlator and DSP
12-bitDigitizer
Analog fiber-optic cable
On-lineCalibration
Data Storage
LAN
Internet
Burstmonitor(s)
RFImonitor(s)
RF Converter Room IF Processor Room
Control Room
RF-IFconverter
Bac
k-en
d
LOdistribution
Polyphase Filter Bank
1-bit Sampler
Front-end
Element
Com
puti
ng
Sys
tem
From other
antennas
IAU Meeting 2006 Aug 21 NJIT Center for Solar Terrestrial Research 26 / 22
FASR Science Community Input
• International Science Workshop, 2002 May, International Science Workshop, 2002 May, Green Bank, WVGreen Bank, WV
• Special session, 2002 Special session, 2002 American Astronomical American Astronomical SocietySociety meeting meeting
• Kluwer ASSL* Book: Kluwer ASSL* Book: Solar & Space-Weather Solar & Space-Weather Radiophysics Radiophysics (17 chapters on all aspects of (17 chapters on all aspects of radiophysics of the Sun and inner heliosphere, radiophysics of the Sun and inner heliosphere, will appear by end of summer)will appear by end of summer)
*Astrophysics & Space Science Library*Astrophysics & Space Science Library
IAU Meeting 2006 Aug 21 NJIT Center for Solar Terrestrial Research 27 / 22
Coronal MagnetogramsCoronal Magnetograms Accurate Accurate
simulation of simulation of FASR coronal FASR coronal magnetograms of magnetograms of potential and non-potential and non-potential active potential active region, and region, and difference difference compared with compared with current-density current-density map from the map from the model.model.
Accurate Accurate simulation of simulation of FASR coronal FASR coronal magnetograms of magnetograms of potential and non-potential and non-potential active potential active region, and region, and difference difference compared with compared with current-density current-density map from the map from the model.model.
from Gary et al. 2004