Transcript Monitoring of interplanetary and ionosphere scintillations

Monitoring of interplanetary and
ionosphere scintillations at the
frequency 111MHz
S.A.Tyul’bashev, V.I.Shishov, I.V.Chashei,
I.A.Subaev
Pushchino Radio Astronomy Observatory
(PRAO ASC LPI)
Aberystwyth - 2009
Plan of report:
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About project
About IPS observations
Sensitivity of observations
Results
Conclusion
Картинка нарисованная
• Monitoring of interplanetary and ionospheric
scintillations give us possibility to find the
sizes of coronal mass ejection (CME) and the
velocity of CME
• Optimal interplanetary scintillations
(frequency 100MHz) have been observed at
scales 0.3a.u. (20 degrees from sun) before
1a.u. (60 degrees)
Different methods of sun
activity estimations
• Strong sources (the problem of angular size of
compact components):
• Weak sources (2 kind of confusion):
• Very weak sources (confusion of compact
sources)
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averaging in boxes
Observations:
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Large Phased Array
Affective area 20000-25000m^2
111MHz; τ=0.1s; bandwidth=600kHz; 1.5MHz
Data of observations 2003–2006 (irregular
observations) 2007– 2008 (monitoring programme)
• 8 or 16 beams
SNR and sensitivity
Results:
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The method of simultaneous IPS and ISS monitoring is
used for investigation of CME;
The dependence of IPS index on day time was found: the
maximal value of mIPP is about 0.3, the minimal value in
the night time is about 0.1.
Weak variations of IPS index from day to day were found
as for day time so for night time.
ISS indexes mIon are smaller than IPS indexes mIPP in the
day time, and are comparable in the night time mIon  mIPP.
During the years 2006-2008 the state of interplanetary
plasma and ionosphere was comparably quiet.
On October 2008 (deep minimum of solar activity) we
observed very strong ellipticity
Conclusion and plans:
• The coefficient of asymmetry give us good
opportunity to investigate sun activity (CME) at
small angular scales (now 3 square degrees)
• 128 beams (64 degrees on the sky), which we will
use for monitoring in 2011, will give us good
opportunity of CME investigation.
• We plan that sensitivity IPS observations will be
equivalent the density of scintillating sources 1
source per 1 square degrees in 2011