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A prototype service to monitor the ionospheric
scintillations J.J. Valette, P. Yaya, B. Nhun
Fat (CLS) P. Lassudrie-Duchesne, R. Fleury
(ENSTB) ESA
Pilot Project for Space Weather Applications
PARTNERSHIP
Disturbances in the ionosphere especially in the
equatorial region are due to strong
irregularities on electron concentration in the E
and F regions. Typical turbulences associated
with the scintillations of signals propagating in
the plasma medium have an extension of a few
hundred meters and a characteristic period of the
ions recombination processes from below 0.01s up
to a few seconds. The phenomena may last several
hours with major intensity after sunset (along
the Equator). It produces strong and rapid
amplitude and phase fluctuations of a GPS
propagating signal.

PROCESSING
CALIBRATION
SERVICE PROTOTYPE
GPS Permanent network perturbations analyses that
lead to empirical scintillation index - L2
signal tracking losses cycle slips - Phase
fluctuations - Signal-to-noise
S1 and S2 amplitudes or phases RINEX data
available from the IGS network need to be
calibrated. The proposed calibration scheme
involves the use of a Ionospheric Scintillation
Monitor (ISM) collocated with an IGS station.
Some comparisons have been done with an ESA ISM
at Douala (Cameroon). Kourou will soon be equiped
with an ISM for this purpose.

• YELLOWKNIFE RINEX amplitude data (IGS, 1s
  samples)
• S1 S2

(P 1 min average)
multipaths
Ionosphericeffect
http//scintillations.cls.fr/
PRODUCTS
KOUROU seasonal/diurnal variations
7 Nov. 2004 - Magnetic storm monitoring Hourly
maps - 1 s GPS data (60 sites)
5 8 Nov. 2004 - Magnetic storm monitoring Daily
maps - 30 s GPS data (250 sites)
2 permanent receivers (ESA/ESOC) at
KOUROU ASHTECH UZ-12 (kour) JPS LEGACY (kou1)
Max activity expected during the equinox 1-30
March 2004 (Kp max6)
Min activity expected during the solstices1-30
June 2004 (Kp max5)
00h TU Kp 1
Kp 2
ASHTECH UZ-12 (kour, 30 s samples)
March 2004

21h TU Kp 6
June 2004
Kp 9
JPS LEGACY kou1, 30 s samples)
Scintillation intensity distribution March 2004
about 3000 events (gt0.25) June 2004 about 100
events (gt0.25)
First European Space Weather Week, Noordwijk,
29th Nov. - 3 Dec. 2004