ISSN 10693513, Izvestiya, Physics of the Solid Earth, 2014, Vol. 50, No. 4, pp. 575–586. © Pleiades Publishing, Ltd., 2014.
Original Russian Text © V.O. Mikhailov, E.A. Kiseleva, E.I. Smol’yaninova, P.N. Dmitriev, V.I. Golubev, Yu.S. Isaev, K.A. Dorokhin, E.P. Timoshkina, S.A. Khairetdinov, 2014,
published in Fizika Zemli, 2014, No. 4, pp. 120–130.
575
1. INTRODUCTION
Satellite radar interferometry is nowadays one of
the actively developing directions in the Earth’s stud
ies from space. The images taken by the interferomet
ric synthetic aperture radars (InSAR) are used for con
structing digital elevation models (DEM) and estimat
ing subtle displacements of the Earth’s surface and
engineering objects. The first estimates of the surface
displacements were obtained with the use of interfero
grams generated based on two radar images obtained
from locally parallel orbits (the so called differential
interferomety, DInSAR). The interferograms show
the relative phase shift of two reflected radar signals
measured during the repeated surveying of the same
object. This phase shift is due to the displacement of
the reflecting object during the time interval between
the surveys; however, it also depends on the changes in
the atmospheric conditions, vegetation, and snow
cover. The errors of orbit determination and DEM also
contributed to the phase shift. This significantly
reduces the possibilities of the methods of differential
interferometry, although there are extensive publica
tions on determining the displacement fields in the
regions of the earthquakes, exploitation of oil and gas
deposits, on the glaciers, and volcanoes by DInSAR
methods. The review of some results can be found, for
instance, in (Mikhailov et al., 2010; 2012).
Various methods for solving the problems of differ
ential interferometry have been developed so far. One
of the suggested approaches is the persistent scatterer
(PS) techniques. The main idea of these methods
(referred to as the PSInSAR techniques) is to simul
taneously analyze a series of interferograms, on which
only the pixels with a stable, in a certain sense, behav
ior are identified and used in the further study (Fer
retti, Prati, and Rocca, 2001). The existing algorithms
of PSInSAR methods differ, inter alia, by the mathe
matical formalism of stable behavior. For example, in
the methods suggested in (Ferretti, Prati, and Rocca,
Some Problems of Landslide Monitoring Using Satellite Radar
Imagery with Different Wavelengths: Case Study
of Two Landslides in the Region of Greater Sochi
V. O. Mikhailov
a
, E. A. Kiseleva
a
, E. I. Smol’yaninova
a
, P. N. Dmitriev
a
, V. I. Golubev
a
,
Yu. S. Isaev
b
, K. A. Dorokhin
b
, E. P. Timoshkina
a
, and S. A. Khairetdinov
a
a
Schmidt Institute of Physics of the Earth, Russian Academy of Sciences,
ul. Bol’shaya Gruzinskaya 10, Moscow, 123995 Russia
email: mikh@ifz.ru
b
OAO Lenmetrogiprotrans Scientific Research and Design Institute,
ul. Bol’shaya Moskovskaya 2, St.Petersburg, 191002 Russia
Received February 19, 2014; in final form, March 3, 2014
Abstract—The problems of processing and interpreting the data provided by radar satellite interferometry for
the conditions of landslides covered by vegetation are analyzed in two case studies of landslides in the North
ern Caucasus in the region of Kepsha and Mamaika villages in the vicinity of the railway tunnels. The esti
mates of the displacement fields are obtained by the method of persistent scatterers using the StaMPS pro
gram package. The fiveyear experience of landslide monitoring at hillsides shows that in the unfavorable
conditions of satellite radar interferometry, proper selection of the strategy of satellite image processing is
vital. In the present paper, we discuss, in particular, the crop selection, the selection of the master image, ref
erence area, and digital elevation model. For the landslide located in the sparsely populated region near Kep
sha village, we used the data from the ascending and descending tracks of the longwavelength ALOS and
shorterwavelength ENVISAT satellites. For the landslide in the region of Mamaika village with a large num
ber of different buildings serving as good scatterers for radar signals, we used the images from the ENVISAT
and from TerraSAR satellite, which transmits even shorter waves. The average lineofsight (LOS) displace
ment velocities V
LOS
for the landslide near Kepsha village measure at most 100 mm per annum, which means
that this landslide has remained stable at least since 2004. The landslide in Mamaika village is significantly
more active. The average LOS displacement velocities in the active part of this landslide attain 60 mm per
annum. The artificial corner reflector installed on the segment of the landslide where natural scatterers of
radar signal are absent made it possible to estimate the LOS displacement velocity on this segment of the slope
at 44 mm per annum.
DOI: 10.1134/S1069351314040107
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