Multi-frequency and multi-point Doppler sounding with application to 3D investigation of Gravity waves and other ionospheric perturbations

0508479 - ÚFA 2020 DE eng A - Abstrakt
Chum, Jaroslav - Laštovička, Jan
Multi-frequency and multi-point Doppler sounding with application to 3D investigation of Gravity waves and other ionospheric perturbations.
IUGG 2019 Abstract Book. Potsdam: International Union of Geodesy and Geophysics, 2019. A03p-223.
[IUGG General Assembly /27./. 08.07.2019-18.07.2019, Montréal]
Institucionální podpora: RVO:68378289
Klíčová slova: upper atmosphere * ionosphere * gravity wave * continuous doppler sounding
Obor OECD: Meteorology and atmospheric sciences
http://iugg2019montreal.com/abstract-book.html

Continuous Doppler sounding is a useful tool to investigate short-time fluctuations in the ionosphere. We
present analysis of gravity wave (GW) propagation in the upper atmosphere and ionosphere in 3D. It is based
on multi-point and multi-frequency continuous Doppler sounding in the Czech Republic. Specifically, Doppler
sounding system consists of three transmitters forming a triangle (size about 70 km) and one receiver at each
frequency. The transmitters and receivers operating at three different frequencies (3.59, 4.65, and 7.04 MHz)
are collocated. Sounding radio waves of various frequencies reflect at different altitudes. Consequently, nine
different sounding signals reflect from nine different points in the ionosphere and the analysis of time (phase)
shifts among the different sounding signals makes it possible to study GW propagation in 3D. In addition,
attenuation of GWs with height is investigated. The disadvantage is a relatively small number of events that
can be analyzed as critical frequency of the ionosphere foF2 has to be larger than the highest sounding
frequency and also significant cross-correlation between signals reflecting at different altitudes is necessary.
Multi-frequency sounding is also useful for investigation of the ionospheric response to solar flares as
sounding signals of different frequencies experience different Doppler shifts and different attenuations.
Trvalý link: http://hdl.handle.net/11104/0299375