B.V. Jackson Center for Astrophysics and Space Sciences,
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CASS/UCSD IPS 2013 Remote Sensing Solar Wind Parameters B.V. Jackson Center for Astrophysics and Space Sciences, University of California at San Diego, LaJolla, CA, USA Masayosh i http://smei.ucsd.edu/ http://ips.ucsd.edu/ The Ability of Radio Heliospheric Remote Sensing Observations to Provide Global Solar Wind Parameters ftp://cass185.ucsd.edu/ Presentations/2013_jeju
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The Ability of Radio Heliospheric Remote Sensing Observations to Provide Global Solar Wind Parameters. B.V. Jackson Center for Astrophysics and Space Sciences, University of California at San Diego, LaJolla, CA, USA. ftp://cass185.ucsd.edu/Presentations/2013_jeju. Masayoshi. - PowerPoint PPT Presentation
Transcript of B.V. Jackson Center for Astrophysics and Space Sciences,
CASS/UCSD IPS 2013
Remote Sensing Solar Wind Parameters
B.V. JacksonCenter for Astrophysics and Space Sciences,
University of California at San Diego, LaJolla, CA, USA
Masayoshihttp://smei.ucsd.edu/ http://ips.ucsd.edu/
The Ability of Radio Heliospheric Remote Sensing Observations to Provide Global Solar Wind Parameters
ftp://cass185.ucsd.edu/Presentations/2013_jeju
CASS/UCSD IPS 2013
Remote Sensing Solar Wind Parameters
More Details
IPS (three site- one site)
CASS/UCSD IPS 2013
Remote Sensing Solar Wind Parameters
IPS Radio Systems
The Ootacamund (Ooty), India off-axis parabolic cylinder 530 m long and 30 m wide (15,900 m2) operating at a nominal frequency of 326.5 MHz.
New STELab IPS array in Toyokawa (3,432 m2 array now operates well – year-round operation began in 2011)
CASS/UCSD IPS 2013
Remote Sensing Solar Wind ParametersA model of the power spectra of density fluctuations
To calculate solar wind velocities using a single IPS station, we use a theoretical power spectrum: an integration of scattering layers along the line of sight (z). The spectrum depends on: λ, ε, v, Θ, α (isotropic medium).
Frequency of intensity fluctuations
Diffractive function (Fresnel function)
Visibility function
of the source
Heliocentric distance at the region of IPS (point P)
Wave number of solar wind irregularities
qx² + qy² =q²
Turbulence spectrum follows a potential law
α ≈ 3.5 ± 0.5
Solar wind velocity
Example of the model (log-log):MEXART and STEL observing frequencies.
Fresnel knee
Fresnel knee
Mejia-Ambriz, J., et al., 2013, AGU 2013 Presentation , May, Cancoon, Mexico.
CASS/UCSD IPS 2013
Remote Sensing Solar Wind Parameters
Comparison between Spectrum Fitting and Cross Correlation Methods
Spectrum Fitting Method(Single-station meas.)Speed V1st.=459km/sAxial Ratio=1.07Spectral Index=3.8
3C273 2012/9/3
Cross Correlation Method(3-station meas.)Speed V3st.= 457±13 km/s
from IPS obs. for 3C273 in 2012
V3st. (km/s)
V1s
t. (
km/s
)
Correlation ~0.47
V1st/V3st=1.04±0.24
(Courtesy of M. Tokumaru)
Tokumaru, M., et al., 2013, AOGS 2013 Presentation , June, Brisbane, Australia.
CASS/UCSD IPS 2013
Remote Sensing Solar Wind Parameters
CASS/UCSD IPS 2013
Remote Sensing Solar Wind Parameters
CASS/UCSD IPS 2013
Remote Sensing Solar Wind Parameters
CASS/UCSD IPS 2013
Remote Sensing Solar Wind Parameters
The Marquardt Method
• 1) Inverse Hessian Method– A * xm = b
– A * xi = -Grad(chiSq) + b
– xm – xi = A-1 * (-Grad(chiSq) )
• 2) Gradient Descent Method– dx = C * Grad(chiSq)
CASS/UCSD IPS 2013
Remote Sensing Solar Wind Parameters
STEL: 298.000
Single Site: 303.437 Diff: -5.43671
3.1060 2.2460 24.6000 327.0000 0.0001
Alpha AR Elong. theta
3.1060 2.2460 24.6000 0.0001
STEL SS Diff.
298.000 303.437 -5.43671
CASS/UCSD IPS 2013
Remote Sensing Solar Wind Parameters
Alpha AR Elong. theta
3.6156 1.5255 27.5000 0.0028
STEL SS Diff.
253.000 249.565 3.43510
CASS/UCSD IPS 2013
Remote Sensing Solar Wind Parameters
Alpha AR Elong. theta
3.6888 0.6644 32.4000 0.0005
STEL SS Diff.
307.000 305.406 1.59369
CASS/UCSD IPS 2013
Remote Sensing Solar Wind Parameters
• v0 = 600
CASS/UCSD IPS 2013
Remote Sensing Solar Wind Parameters
• V0=344.229
CASS/UCSD IPS 2013
Remote Sensing Solar Wind Parameters
