Low-latitude Ionospheric Sensor Network (LISN)

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Low-latitude Ionospheric Sensor Network (LISN)
C. E. Valladares, Boston College V. Eccles, Space
Environment Corporation E. Kudeki, University of
Illinois R. F. Woodman, Instituto Geofisico del
Peru J. W. Wright, University of Colorado
Caracas, November 18, 2005
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Project Goals
To build and operate the first Distributed
Observatory across the western half of South
America to study the low-latitude ionosphere.
To deploy many small instruments in a region
bounded to the north, west and south by the
continental boundaries and to the east by the 55
W meridian. To transmit real-time measurements
to a server that will assimilate the observable
parameters and calculate geophysical
quantities. The instruments to be deployed
are 49 GPS receivers, 5 dynasondes and 5
magnetometers.
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Scientific Tasks
To develop tools to forecast the initiation of
the equatorial spread-F (ESF) phenomenon in a
regional basis. To study the electrodynamics
of the low-latitude ionosphere during magnetic
quiet and disturbed conditions. The distributed
observatory will be able to measure the
conductivity along a flux tube ? tell us how
unstable is a flux tube to the initiation of
ESF. It will measurement E region (100 km)
densities at both feet of an unstable field line
? known to stabilize flux tube.
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Fundamental principle of the dynasonde
Pulsed radio waves of up to 20 MHz (15m
wavelength) may be totally reflected in the
ionosphere, giving strong echoes even with rather
low transmitted power (1 kW).
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Geographic Location of 5 dynasondes
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ESF echoes, GPS scintillations and TEC depletions
A westward tilted plume reached 1400 km before
2100 LT. This altitude maps to the F region at 9
N.
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UHF Scintillations Frequency Spread F observed
on Jan 27, 2003
TEC values
Universal Time
0200
0300
0400
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Real-time data flows of LISN data and
assimilation results
Real-time link
(1) Low-latitude Ionospheric model, (2)
low-latitude electrodynamics model, (3) model of
ground-based magnetic perturbations for a 3-D
current system (4) Kalman filter program.
Real-time link
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GPS receiver to be selected
LEICA 1200 PRO
TRIMBLE NetRS
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GPS possible locations to be deployed as part of
LISN
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Initial plan of GPS deployment
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Scientific and Technological Impact
We offer a plan to forecast Space Weather (ESF
in particular). Provide ionospheric corrections
to WAAS-type systems. There is a need for
real-time specification of ionospheric density.
Applications to Earth Sciences and Geodesy. GPS
Meteorology.
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BC can provide the following equipment
GPS receiver and PC (laptop or Portable)
Local server Solar panel, battery or a
long-term UPS Internet connectivity (DSL)
Cover some deployment expenses
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Observable Parameters
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Flow diagram of the Ensemble Kalman filter for
LISN