1. IPS and SMEI Observation Comparison
Current STELab IPS Heliospheric Analyses STELab interplanetary scintillation (IPS) 327 MHz array near Fuji

2. IPS and SMEI Observation Comparison
Scintillation Level (g-level) Heliospheric Analysis Intensity interplanetary scintillation (IPS) g-levels.

3. IPS and SMEI Observation Comparison
IPS 3D Reconstruction
20 May – 05 June 2003, (28 May ‘Halo’ CME)
Pressure (ρ = CnV2) Observations at Mars |

4. CSSS Model Inclusion into the Tomography
IPS and SMEI Observation Comparison
Problem – the most fundamental parameter magnetic field is unknown.
IDEA !
CSSS Model Inclusion into the Tomography
(Grad. student Tamsen Dunn)

5. IPS and SMEI Observation Comparison
Bastille Day Event Period 2000/ 07/14 corr when in situ response smoothed by 7 days

6. IPS and SMEI Observation Comparison
IPS C.A.T. Analysis

7. IPS and SMEI Observation Comparison
Time Series for 3 Models and 18-hr Avg. In Situ Data for CR 1965

8. IPS and SMEI Observation Comparison
Faraday Rotation

9. Magnetic Cloud Model Simulation (Justin Kasper LWS, Boulder 2004)
IPS and SMEI Observation Comparison
Magnetic Cloud Model Simulation (Justin Kasper LWS, Boulder 2004)
Method
Fit observed flux rope at 1 AU with simple flux tube model
Map flux tube back to Sun at constant speed
Scale flux tube dimensions linearly
Calculate RM due to rope every 10 minutes
Measured values of the magnetic field as a function of distance of spacecraft through the magnetic cloud. The red lines are the best fit of the simple cylindrically symmetric flux rope model to the observations.

10. Simulations of Observations During Transit
IPS and SMEI Observation Comparison
Simulations of Observations During Transit
(Justin Kasper, LWS, Boulder 2004)
(b)
(a)
(a-f): Images of the rotation from the first flux rope that LOFAR-type instrument would have observed as a function of time since the eruption of the CME. The clock indicates the time since the CME erupted. The pixel color indicates the Faraday Rotation at 60 MHz (Note that the scale changes for each image!). In (a), the rope has not yet produced an observable change in the rotation, and the ~2 degree uncertainty of the LOFAR measurements is apparent. In (b) approximately 20 sources have undergone very large rotations. The rope gradually expands to fill the sky in (c-e). In (f) Earth is inside the flux rope.

11. IPS and SMEI Observation Comparison
(Justin Kasper LWS, Boulder 2004)
(c)
(d)
(e)
(f)

12. IPS and SMEI Observation Comparison The MILEURA WIDEFIELD ARRAY (MWA)
A joint US-Australia project
Kick-Off meeting San Diego 4-7 June 2006

13. PARTNERS AND COLLABORATORS
IPS and SMEI Observation Comparison
MWA: A joint US-Australia project
PARTNERS AND COLLABORATORS
PARTNERS
• MIT: Haystack Observatory and Center for Space Research
• Harvard-Smithsonian Center for Astrophysics
• Australia Telescope National Facility (ATNF)
• University of Melbourne (AU)
• Australian National University (AU)
Curtin University of Technology (AU)
• Office of Science Innovation (Western AU Govt.)
COLLABORATORS in HELIOSPHERIC SCIENCE
• University of California, San Diego
• Nagoya University/STEL, Japan
• University of Bonn, Germany
• University of Sydney, Australia
• AF Research Laboratory
(From Joe Salah)

14. MILEURA WIDEFIELD ARRAY (MWA) – LOW FREQUENCY DEMONSTRATOR (LFD)
IPS and SMEI Observation Comparison
MILEURA WIDEFIELD ARRAY (MWA) – LOW FREQUENCY DEMONSTRATOR (LFD)
(Joe Salah)
(At Australian proposed SKA Site)
Mileura, Western Australia
- RFI environment
- Infrastructure flexibility
General Characteristics:
▪ Frequency coverage: MHz
▪ Wide field (~1000 deg2)
▪ A science-focused demonstrator
► Conduct key science experiments
► Demonstrate technology
Projected schedule:
► 2005: Prototype field tests
► : Construction
► : Scientific observations
 Project status:
Approved for funding – formal award expected 1 June

15. SCIENTIFIC MOTIVATION
IPS and SMEI Observation Comparison
SCIENTIFIC MOTIVATION
THREE FOCUSED EXPERIMENTS:
Measurement of red-shifted 21 cm power spectrum from the
Epoch of Reionization in the early universe.
Observation of the solar wind structure from near the Sun to 1 AU
Interplanetary Scintillations
Faraday Rotation: emphasis on CME magnetic field
Type II solar burst imaging
Detection of radio transients
(From Joe Salah)

16. MWA-LFD SPECIFICATIONS
IPS and SMEI Observation Comparison
MWA-LFD SPECIFICATIONS
Frequency: MHz
500 antenna ‘tiles’, each with 4 x 4 crossed dipoles
Imaging field of view: 50o -15o ( MHz)
Phased array mode: 16 beams
Total collecting area: 8000 m2 (at 200 MHz)
Bandwidth: 32 MHz
Sensitivity: ~20 mJy for 1 sec int. (at 200 MHz)
Spatial extent of array: 1.5 km core + extensions to 3 km
Resolution: ~2 arcmin (at 200 MHz)
Polarization: Full Stokes
(From Joe Salah)

17. Physical Layout of Array Core
IPS and SMEI Observation Comparison
Physical Layout of Array Core
Central Processor
(From Joe Salah)

18. IPS and SMEI Observation Comparison
AUGMENTATION FOR SOLAR BURST IMAGING
Core
Antenna tile
INITIAL SUB-ARRAY AT MILEURA: ~ end 2007
Angular resolution: 2 arcmin (200 MHz)
Time resolution: 50 msec (temporary)
Frequency resolution: 64 KHz across 4 MHz band
(From Joe Salah)

19. IPS and SMEI Observation Comparison
B. Jackson and P. Hick (UCSD), M. Kojima (STEL)
MWA-LFD will provide:
An increase in the number of independent observations (beams) by factor of 16
– this addresses the most constraining bottleneck in IPS
Enhanced sensitivity by a factor ~5 with an increase in number of IPS sources observed
Increased spectral SNR (factor of 3-4) due to longer
observation times allowed by the independent beams
Coverage in southern hemisphere and new longitude adding to global IPS coverage (STEL, EISCAT, OOTY, MEXART)
(From Joe Salah)

20. PRINCIPLE OF FARADAY ROTATION (FR)
IPS and SMEI Observation Comparison
PRINCIPLE OF FARADAY ROTATION (FR)
(From Joe Salah)
Rotation Measure (RM)
For RM = 1 rad m-2
 = 60° at 300 MHz
 = 800° at 80 MHz
Technique has been successfully applied using spacecraft telemetry signals (2.3 GHz)
(Pioneer,Helios, Cassini) as spacecraft pass behind Sun (Bird, Pätzold, Jensen...)
or with VLA (1.5 GHz) observing galaxies through heliosphere (Mancuso, Spangler…)
For the MWA: Estimate 1 polarized source per 3-4 deg2 (Haverkorn et al.)
Potentially higher resolution using polarized galactic background

21. Challenges for the application of Faraday rotation
IPS and SMEI Observation Comparison
Challenges for the application of Faraday rotation
Detailed survey for polarized sources at MHz in Southern Hemisphere
Unfold rotation ambiguity
Use multiple frequencies within array band
Remove rotation effects due to the Earth’s ionosphere:
Use GPS for absolute calibration (AFRL contribution acknowledged)
Use array calibration for small scale distortions across array
Invert Faraday rotation to determine B
Need measurement of plasma density [IPS, SMEI, STEREO]
Demonstrate algorithms and accuracy (UCSD collaboration)
Demonstrate from ground to confirm overall accuracy (~4o for 20 mJy in 5 min)
Operations:
Need trigger (external, radio burst) to prompt FR observations of event at high cadence
(From Joe Salah)

22. IPS and SMEI Observation Comparison
SOLAR BURST IMAGING
Type II solar bursts are generally associated with fast CMEs and shocks, are usually observed at frequencies below 150 MHz and drift at ~ -0.2 MHz/s, lasting many minutes.
The frequency-time structure of Type II bursts has been well characterized through past observations. In order to make further progress in understanding their relationship to CMEs, information on spatial structure (images) and location are needed.
The augmented MWA-LFD has wide field-of-view, high dynamic range snapshot-imaging capability, and angular resolution to observe solar Type II bursts. The ~2 arcmin angular resolution will allow precise location of the bursts.
(From Joe Salah)

23. IPS and SMEI Observation Comparison
The first antenna tile at Mileura
Early Deployment Tests at Mileura (March-September 2005)
(From Joe Salah)
Early Deployment Tests conducted by ANU, Curtin Univ., Univ. Melbourne, and MIT

24. IPS and SMEI Observation Comparison
RFI environment at Mileura
Deep integrations for 60 min
Deep integration for 10 hours
102 MHz
131 MHz
189 MHz
187 MHz
327 MHz
(From Joe Salah)

25. IPS and SMEI Observation Comparison
Interferometry tests (2 and 3 antenna tiles – 145 meters)
Correlated amplitude and phase on Sun (96 MHz) on 27 April 2005
(From Joe Salah)

26. IPS and SMEI Observation Comparison
MWA-LFD SOLAR BURST OBSERVATIONS
15 September 2005
04: : : : : : :13 UT
TIME
Each panel
= 60 seconds
Res: 50msec
FREQUENCY
MHz
Color: signal amplitude in dB, spanning a range of ~12 dB.
(From Joe Salah)
Res: 16 kHz

27. IPS and SMEI Observation Comparison
SUMMARY
The Mileura Widefield Array (MWA) is a new-generation low frequency
radio sensing instrument, enabled by modern digital signal processing,
high speed signal transport, and powerful computing.
Characteristics: high sensitivity, wide-field coverage, multiple beams.
Location: extremely radio-quiet site in Western Australia
Planned operation: initial phase by ~end-2007, full system 2008.
ANTICIPATED MWA SCIENCE RETURNS FOR HELIOSPHERIC SCIENCE:
Measurements of large scale structure in solar wind plasma,
and tracking of CMEs from ~0.25 AU to 1 AU and beyond through IPS.
Characterization of heliospheric magnetic field, and determination of the evolution of CME magnetic field through Faraday rotation as a key input
to space weather predictions.
Imaging of Type II bursts with fine angular resolution (~2 arcmin)
(From Joe Salah)

28. IPS and SMEI Observation Comparison
Summary:
Still needed:
a) A lot more work.
b) SMEI - 3D reconstruction analysis from the whole time period observed by SMEI and comparison with IPS.
c) Inversion of the Faraday Rotation observations to determine and remotely-sense 3-component magnetic fields.
d) Work on the SKA LFD (MW array telescope), Faraday rotation, Ionisphere: Who wants to help?