Research Information System
Hastaoğlu K. Ö. (Executive), Poyraz F., Türk T., Koçbulut F., Balık Şanlı F., Yılmaz I., et al.
TUBITAK Project, 2012 - 2015
Recently PS-InSAR method is generally used to determine deformations caused by the earthquake,
movements in volcanic areas, subsidence in hydrological, geological, mining or urban areas.
However, this method is not used so often in determining the movements of landslides perhaps
because of being a relatively new method. But it is seen in the few studies done for this aim
that the PS-InSAR method can be successful in monitoring landslide movements. The main
purpose of this proposed project is to determine the existing areal deformation by using
modern and spatial PS-InSAR and GNSS methods. By comparing the results that are obtained
by using these two methods the usage of PSInSAR on landslide will be searched. According
to this purpose, the Koyulhisar region has been selected as the study site. 53 GPS points has
been established throughout the region. At these GPS points, based on Rapid Static, one-hour
period measurements has been made 10 times each day within 3 days in order to obtain GPS
points’ three dimensional (North, east, up) velocity values. In addition, Envisat and Terrasar-x
radar satellites’ SAR images have been obtained, via the projects that were offered to German
Aerospace Center and European Space Agency. These images have been evaluated with
STAMPS software. Thus, slip surfaces of the landslide region in the direction of the line of sight
(LOS) was obtained by PS-InSAR method. Velocity values obtained by the PS-InSAR method are
one dimensional, therefore these values are not suitable for comparison with the GPS results.
Because of this, GPS based velocity values’ directions were converted into the LOS direction
to be compared with PS-InSAR results. For comparison process, point data obtained from both
GPS and PS-InSAR methods were used to create interpolated maps of the landslide region.
As a result of this comparison, the GPS method was found more effective when obtaining local
deformations based on point data while the PS-InSAR method was better at the areal movement
obtainment of the landslide region. However, considering the Koyulhisar landslide region as it
engages in movements independent from the main mass movement, using both methods together
will gather better results.