The Frequency Agile Solar Radiotelescope AUI, NRAO, UCB, CIT, NJIT, - PowerPoint PPT Presentation

The Frequency Agile Solar Radiotelescope AUI, NRAO, UCB, CIT, NJIT, UMd, UM

The Innovation Ultra-wideband imaging spectroscopy of the solar atmosphere from the chromosphere to the outer corona with temporal, angular, and spectral resolution matched to the physical process that occur.   Brightness temperature as a B x , y ,  , t ,  T function of position, frequency, time, and polarization The entire solar atmosphere will be imagined in 3D from the mid-chromosphere to the outer-corona once every second! ฀ 

Frequency 50 MHz - 21 GHz FASR range Data channels, Specifications bandwidth, freq. 2/500 MHz/4000/20 channels, int. ms (descope) time A: ~45 (990 pairs) Number B: ~15 (105 ) FASR A: ~2.5-21 GHz antennas C: ~15 (105) FASR B: ~0.25-3 GHz A: 2 m FASR C: ~50-300 MHz B: 6 m Size antennas C: LPD tiles or similar Polarization Stokes IV(QU) Proposed site is OVRO Angular 20/  9 arcsec resolution Footprint ~3 km Field of View >0.5 deg

The Science  Coronal Magnetic Fields  Coronal magnetography  Spatiotemporal evolution of fields  Role of electric currents in corona  Coronal seismology  High energy solar physics  Magnetic energy release  Plasma heating and dynamics  Electron acceleration and transport  Origin of SEPs  Drivers of Space Weather  Birth & acceleration of CMEs  Prominence eruptions  Origin of SEPs  Fast solar wind streams

The Science  The “thermal” solar atmosphere ◦ Coronal heating - nanoflares ◦ Thermodynamic structure & dynamics ◦ Formation & structure of filaments  Solar Wind ◦ Birth in network ◦ Coronal holes ◦ Fast/slow wind streams ◦ Turbulence and waves  Synoptic studies ◦ Radiative inputs to upper atmosphere ◦ Global magnetic field/dynamo ◦ Flare statistics

Recent Developments • FASR DDP funded by NSF/ATM in 2006 Development of ultrawideband feeds and integrated amps initiated • FST program funded by NSF/AST ATI in 2006 RFI mitigation • FASR Reference Instrument completed O&M Plan delivered in June 2007 FASR descope/rescope • Preliminary proposal submitted to the NSF/ATM MSI Opportunity program in January 2008 • Full proposal submitted to NSF in June 2008 for $25M Funding decision is imminent!

Definition and Variance of Spectral Kurtosis 4 A  k K ( f ) Dwyer (1983) k 2 2 A k  N 1     2 2 ikn / N 4  2 X x e X 2 X k n k k  SK ( f )  Vrabie (2003) Spectral Kurtosis n 0 k 2   2 X A iB X k k k k  2  2 k Nita (2007) Spectral Variability V  k 2 k   2 2 P A B   k k k 2 P   M k   M 1      2 M 1 P     P k k k    2 2 2 P P k k k     24 / M , k 0 , N / 2  2  Var V   k  4 / M , k 1 ,..., ( N / 2 1 )

Performance and limitations of SK estimator

Software Implementation of RFI excision algorithm

CASPER Hardware Implementation of RFI excision algorithm