In the last decades, the development of space geodesy methods has allowed much more
accurate observations of planetary surface dynamics than before. The various SAR satellites,
like global navigation systems, make their observations in different microwave frequency
ranges (1-10 GHz). The Earth's atmosphere is transparent to the microwave signal,
but the factors affecting wave propagation (propagation direction and velocity) in
the medium are time-dependent, the medium is anisotropic, inhomogeneous and, in the
case of the ionosphere, dispersive. Without the correction of such atmospheric artifacts
the resulting signal delay is evaluated as a displacement during processing, which
can be in the order of tens of meters.In order to get information about the actual
geophysical processes from the displacement values derived from satellite data, the
effects on wave propagation must also be taken into account. Radar interferometric
methods are particularly suitable for detecting processes with velocities in the order
of a few mm/year, but are limited by the lack of quantitative knowledge of the signal
delay in the wave propagation, which is of particular importance for the study of
processes on a regional scale.Wave propagation in the neutral atmosphere is mostly
distorted by refraction due to water vapour, and the correction is complicated by
the dynamic variation of the water vapour content and the inaccurate knowledge of
the atmospheric water vapour. In the ionosphere, in addition to Faraday-rotation and
electron density dependent refraction, the dispersive nature of the medium is another
source of error.Transient atmospheric phenomena (frontal and thunderstorm systems,
ionospheric disturbances, sporadic E layers, etc.), which are predominantly inhomogeneous
in nature, further complicate the correction of their effects, but also provide an
excellent opportunity to study them. The Sentinel-1 satellite images cover an area
of 250 km x 250 km with a resolution of 5 m x 20 m. This resolution may prove useful
for studying atmospheric inhomogeneities.In radar interferometric processing, virtual
displacements generated by atmospheric phenomena can be investigated in areas that
are assumed to be geologically stable and contain well-identified objects that provide
strong signal reflection. For the latter, corner reflectors points specifically designed
for this purpose have already been developed.In the area of Sopron (Hungary), there
are 4 such installed permanent artificial reflectors. By including these points and
by comparing measurements from the local ionosonde and meteorological station, we
have studied the influence of atmospheric phenomena on radar interferometric processing
and the applicability of radar interferometry for the study of atmospheric phenomena.
