1. The Frequency Agile Solar Radiotelescope (FASR) Dale E. Gary New Jersey Institute of Technology

2. IAU Meeting 2006 Aug 21NJIT Center for Solar Terrestrial Research2 / 22

3. IAU Meeting 2006 Aug 21NJIT Center for Solar Terrestrial Research3 / 22 FASR Instrument (Antennas) Three arrays, 4.2 km baselines Array Designation Number of Antennas Frequency Range Antenna Size FASR-A High Frequency Array ~100 2-20 GHz 2-30 (goal) 2 m FASR-B Low Frequency Array ~60 0.2-3 GHz 6 m FASR-C Log-Periodic Dipole Array ~40 50-300 MHz 20-300 (goal) Log- dipole

4. IAU Meeting 2006 Aug 21NJIT Center for Solar Terrestrial Research4 / 22

5. IAU Meeting 2006 Aug 21NJIT Center for Solar Terrestrial Research5 / 22 FASR Instrument (Receivers) Broadband RF transmission, Digital FX Correlator QuantitySpec Frequency Resolution 0.01% (internal) 1-3% (output) Time Resolution 100 ms (FASR-B/C) 1 s (FASR-A) PolarizationStokes IV (QU) Instantaneous Bandwidth~1 GHz

6. IAU Meeting 2006 Aug 21NJIT Center for Solar Terrestrial Research6 / 22 FASR Science Goals Designed to be the world’s premier solar radio facility for at least two decades after completion. Full capability to address a broad range of solar science: 1.Nature and evolution of coronal magnetic fields 2.Physics of flares 3.Drivers of space weather 4.Physics of the quiet solar atmosphere Designed to be the world’s premier solar radio facility for at least two decades after completion. Full capability to address a broad range of solar science: 1.Nature and evolution of coronal magnetic fields 2.Physics of flares 3.Drivers of space weather 4.Physics of the quiet solar atmosphere

7. IAU Meeting 2006 Aug 21NJIT Center for Solar Terrestrial Research7 / 22 Objectives to Measurements Key Science Objectives Science Goals Measurement Goals Observables Emission Mechanism Measurement Requirements 1  D  T b (K)  (s) Objective 1: The nature and evolution of coronal magnetic Fields A: Coronal Magneto- graphy of active regions Strong magnetic fields (>150 G) a: Active region multi- T b maps Gyroresonance1-181%300010001800 B: Coronal Magneto- graphy of the quiet Sun LOS magnetic Fields b: Full-Sun multi- T b maps Free-free1-201%10003001800 C: Magnetic connectivity of the corona to the heliosphere Coronal field and topology 1a, 1bSee above----- c: Active region multi- poln Maps Mode-coupling depolarization surface 1-201%1000 1800 d: dm- and m- type III bursts Plasma0.03-31%1000 10 5 0.01

8. IAU Meeting 2006 Aug 21NJIT Center for Solar Terrestrial Research8 / 22 Magnetic Field Spectral Diagnostics Model spectra along 2 lines of sight: a) negative polarity sunspot, b) positive polarity sunspot. The coronal temperature and the magnetic field strength can be read directly from the spectra. Model from Mok et al., 2004; Simulation from Gary et al. 2004

9. IAU Meeting 2006 Aug 21NJIT Center for Solar Terrestrial Research9 / 22 2D Magnetogram B map deduced from 1—24 GHz spectra (b) match the model (a) very well, everywhere in the region. (c) is a comparison along a line through the center of the region. The fit only works down to 119 G (corresponding to f = 3 f B = 1 GHz) from Gary et al. 2004

10. IAU Meeting 2006 Aug 21NJIT Center for Solar Terrestrial Research10 / 22 Objectives to Measurements Key Science Objectives Science Goals Measurement Goals Observables Emission Mechanism Measurement Requirements 1  D  T b (K)  (s) Objective 1: The nature and evolution of coronal magnetic Fields A: Coronal Magneto- graphy of active regions Strong magnetic fields (>150 G) a: Active region multi- T b maps Gyroresonance1-181%300010001800 B: Coronal Magneto- graphy of the quiet Sun LOS magnetic Fields b: Full-Sun multi- T b maps Free-free1-201%10003001800 C: Magnetic connectivity of the corona to the heliosphere Coronal field and topology 1a, 1bSee above----- c: Active region multi- poln Maps Mode-coupling depolarization surface 1-201%1000 1800 d: dm- and m- type III bursts Plasma0.03-31%1000 10 5 0.01

11. IAU Meeting 2006 Aug 21NJIT Center for Solar Terrestrial Research11 / 22 B l from Free-Free Emission With sufficient polarization sensitivity, B l can be deduced everywhere down to ~ 20 G using: where n is the spectral index from Gelfreikh, 2004—Ch. 6 from Gary & Hurford, 2004—Chapter 4

12. IAU Meeting 2006 Aug 21NJIT Center for Solar Terrestrial Research12 / 22 Objectives to Measurements Key Science Objectives Science Goals Measurement Goals Observables Emission Mechanism Measurement Requirements 1  D  T b (K)  (s) Objective 1: The nature and evolution of coronal magnetic Fields A: Coronal Magneto- graphy of active regions Strong magnetic fields (>150 G) a: Active region multi- T b maps Gyroresonance1-181%300010001800 B: Coronal Magneto- graphy of the quiet Sun LOS magnetic Fields b: Full-Sun multi- T b maps Free-free1-201%10003001800 C: Magnetic connectivity of the corona to the heliosphere Coronal field and topology 1a, 1bSee above----- c: Active region multi- poln Maps Mode-coupling depolarization surface 1-201%1000 1800 d: dm- and m- type III bursts Plasma0.03-31%1000 10 5 0.01

13. IAU Meeting 2006 Aug 21NJIT Center for Solar Terrestrial Research13 / 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

14. IAU Meeting 2006 Aug 21NJIT Center for Solar Terrestrial Research14 / 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)

15. IAU Meeting 2006 Aug 21NJIT Center for Solar Terrestrial Research15 / 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 telescope http://www.astro.umd.edu/~white/gb/

16. IAU Meeting 2006 Aug 21NJIT Center for Solar Terrestrial Research16 / 22 FST System HardwareHardware  1-9 GHz RF  500 MHz instantaneous BW  Record full-res time-domain signal, off-line processing Block DiagramBlock Diagram

17. IAU Meeting 2006 Aug 21NJIT Center for Solar Terrestrial Research17 / 22 Results (RFI) 10000-pt spectra (d = 50 kHz), 10  s time resolution sample of local interference signal10000-pt spectra (d = 50 kHz), 10  s time resolution sample of local interference signal Goal is to identify and excise interference in real timeGoal is to identify and excise interference in real time Hiro Kawakubo and Chris Ruf (U Mich) are studying use of kurtosis statisticHiro Kawakubo and Chris Ruf (U Mich) are studying use of kurtosis statistic Time Frequency

18. IAU Meeting 2006 Aug 21NJIT Center for Solar Terrestrial Research18 / 22 Results (Satellites) First Fringes (GPS satellite, L1 signal, 1575.42 MHz)First Fringes (GPS satellite, L1 signal, 1575.42 MHz)

19. IAU Meeting 2006 Aug 21NJIT Center for Solar Terrestrial Research19 / 22 Results (Satellites) Geostationary Satellite Galaxy 10RGeostationary Satellite Galaxy 10R Can phase information be used for calibration?Can phase information be used for calibration? Overlapping channels are linearly (H and V) polarized, which offers possibility of linear polarization calibrationOverlapping channels are linearly (H and V) polarized, which offers possibility of linear polarization calibration

20. IAU Meeting 2006 Aug 21NJIT Center for Solar Terrestrial Research20 / 22 20 s of FST Amplitude Data B5.1 Flare (2006 Apr 05) Results (Solar)

21. IAU Meeting 2006 Aug 21NJIT Center for Solar Terrestrial Research21 / 22 FST Amplitude & Corrected Phase Burst locations essentially identical from burst to burst, and from one polarization to another

22. IAU Meeting 2006 Aug 21NJIT Center for Solar Terrestrial Research22 / 22 Status and Conclusion FASR is being designed to address an extremely rich range of solar science, utilizing state-of-the-art technology.FASR is being designed to address an extremely rich range of solar science, utilizing state-of-the-art technology. Some aspects of the instrument are currently being prototyped.Some aspects of the instrument are currently being prototyped. Most recent proposal received highest recommendation, but funding has been reduced and delayed by funding agency.Most recent proposal received highest recommendation, but funding has been reduced and delayed by funding agency. Next step is to construct a 10-element prototype array, to be ready by 2010. Proposal to be submitted as soon as possible.Next step is to construct a 10-element prototype array, to be ready by 2010. Proposal to be submitted as soon as possible. FASR is being designed to address an extremely rich range of solar science, utilizing state-of-the-art technology.FASR is being designed to address an extremely rich range of solar science, utilizing state-of-the-art technology. Some aspects of the instrument are currently being prototyped.Some aspects of the instrument are currently being prototyped. Most recent proposal received highest recommendation, but funding has been reduced and delayed by funding agency.Most recent proposal received highest recommendation, but funding has been reduced and delayed by funding agency. Next step is to construct a 10-element prototype array, to be ready by 2010. Proposal to be submitted as soon as possible.Next step is to construct a 10-element prototype array, to be ready by 2010. Proposal to be submitted as soon as possible.

23. IAU Meeting 2006 Aug 21NJIT Center for Solar Terrestrial Research23 / 22

24. IAU Meeting 2006 Aug 21NJIT Center for Solar Terrestrial Research24 / 22 FASR Endorsements 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) 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)

25. IAU Meeting 2006 Aug 21NJIT Center for Solar Terrestrial Research25 / 22 FASR Signal Path Correlator and DSP 12-bit Digitizer Analog fiber- optic cable On-line Calibration Data Storage LAN Internet Burst monitor(s) RFI monitor(s) RF Converter Room IF Processor Room Control Room RF-IF converter Back-end LO distribution Polyphase Filter Bank 1-bit Sampler Front-end Element Computing System From other antennas

26. IAU Meeting 2006 Aug 21NJIT Center for Solar Terrestrial Research26 / 22 FASR Science Community Input International Science Workshop, 2002 May, Green Bank, WVInternational Science Workshop, 2002 May, Green Bank, WV Special session, 2002 American Astronomical Society meetingSpecial session, 2002 American Astronomical Society meeting Kluwer ASSL* Book: Solar & Space-Weather Radiophysics (17 chapters on all aspects of radiophysics of the Sun and inner heliosphere, will appear by end of summer)Kluwer ASSL* Book: Solar & Space-Weather Radiophysics (17 chapters on all aspects of radiophysics of the Sun and inner heliosphere, will appear by end of summer) *Astrophysics & Space Science Library *Astrophysics & Space Science Library

27. IAU Meeting 2006 Aug 21NJIT Center for Solar Terrestrial Research27 / 22 Coronal Magnetograms Accurate simulation of FASR coronal magnetograms of potential and non- potential active region, and difference compared with current-density map from the model. from Gary et al. 2004