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Research Areas
Experimental investigations of ionospheric disturbances of natural
and technogenic origin, based on processing data from the global
network of two-frequency receivers of the GPS-GLONASS navigation
systems.
The use of the international network of two-frequency receivers
of the navigation GPS system that consisted of no less than 1000
sites as of begining 2002 and has been posting its acquired data on
the Internet, opens up a new era in a global, continuous, fully
computerized monitoring of space weather in geospace. In the
immediate future this system will incorporate the use of signals
from a similar Russian system, GLONASS. ISTP SB RAS scientists
have devised methods and the technology of a global GPS detector
of ionospheric disturbances whose high sensitivity makes it
possible to analyze ionospheric disturbances with amplitudes as
large as 10-3 of the background value of total
electron content. In comparison with classical ionospheric radio
probing facilities, this technology provides, for the first time,
a real continuity, high spatial and temporal resolution and
global coverage of the monitoring of ionospheric disturbances.
Priority objectives
- Investigations of the global activity of different-scale
natural ionospheric irregularities in geomagnetically quiet
conditions and during magnetic storms.
- Investigations of global spectral and dynamic
characteristics of traveling ionospheric disturbances.
Verification of the hypothesis about the role of
geomagnetic disturbances as the factor governing the
characteristics of the spectrum of traveling ionospheric
disturbances.
- Investigations of the global ionospheric response to a
sudden commencement of severe geomagnetic storms.
- Investigations of global three-dimensional spectral and
dispersion characteristics of traveling ionospheric
disturbances.
- Investigations of spatial and temporal characteristics of
polarization jet.
- Investigations of the total electron content during active
experiments (particle injection, radio heating, etc.).
- Investigations of shock-acoustic waves generated during spacecraft
launchings, industrial explosions, underground nuclear tests,
and earthquakes. Development of algorithms and of the software
system for detection and localization of sources of technogenic
impacts using data from the navigation GPS-GLONASS systems,
based on the latest achievements in the field of a
comprehensive spatial and temporal processing of signals from
phased antenna arrays.
- Investigations of global characteristics of the atmospheric
response to solar flares using the (developed at the ISTP) new
technology for detection of ionospheric effects of solar flares,
which improves considerably the sensitivity and spatial and
temporal resolution of observations as compared with existing
radio probing methods. Estimation of the sensitivity of the
method of global integration in the case of the detection of
the ionospheric response of weak solar fares and disturbances
of non-solar origin (supernova explosions). determination of
spatial and temporal characteristics of ionospheric response
to large solar flares, including the spatial inhomogeneity of
solar ultraviolet emission flux within the terrestrial radius.
Estimation of the height distribution of the contribution from
this emission to the total electron content disturbance using
the method of shadowing the solar emission flux by the Earth.
Investigation of the dependence of the ionospheric response on
solar flare characteristics (flare class, emission spectrum,
source position on the solar disk, etc.).
- Investigations of spatial and temporal characteristics of
ionospheric response to solar eclipses, and the total solar
eclipses of March 9, 1997, August 11, 1999, and June 21, 2001,
in particular. Determination of the amplitude and delay of the
ionospheric response to eclipse. -More.
- Investigation of global pulsations of total electron content
and their correlation with similar geomagnetic field pulsations.
- Development of the numerical model for total electron content
disturbances of natural and technogenic origin that is
necessary for testing the algorithms and software package
for detection and determining the characteristics of these
disturbances.
- Investigations of the influence of helio-geomagnetic
disturbances of geospace on positioning accuracy in the
GPS-GLONASS navigation systems. Investigations of the physical
mechanisms for slips of range measurements in the GPS-GLONASS
navigation systems, based on data from the global GPS network
and classical monitoring facilities for geospace conditions.
Development of algorithms and the automated software system for
monitoring and forecasting the potential positioning accuracy.
- Study of spectral and statistical characteristics of frequency
Doppler shift, angle-of-arrival variations, and phase
scintillations of decimetric radio signals during the
transionospheric propagation within the GPS satellite orbit.
- Setting up (at the ISTP) of the center for monitoring
technogenic influences and forecasting the potential
positioning accuracy on the basis of real-time analysis
of data from the global GPS system and helio-geophysical
data available on the Internet.
- Creation of the database from the global GPS network spanning
selected time intervals corresponding to different levels of
helio-geophysical disturbances of geospace, seismic activity
and technogenic influences of a different type (spacecraft
launches, industrial explosions, underground explosions).
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