Preliminary analysis of InSAR data over Trondheim with respect to future road development.

Abstract

Frie emneord: Urban geology ; Subsidence ; Interferometry Timely identification of subsidence is important in order to ensure that remediation efforts are successful. Even if subsidence cannot be prevented or stopped, it must be accounted for in new construction planning. Identification and monitoring of ground deformation can be accomplished using a number of surveying techniques. Levelling and GPS are both expensive and the number of benchmarks that can be controlled is limited. Since the early 1990's satellite-based radar interferometry has been used to identify large ground movements due to earthquakes and volcanic activity. Data stacking methods that take advantage of a growing archive of radar images, as well as increasing computing power, have led to a large increase in the precision of the technique. Both linear trends and seasonal fluctuations can be identified using the Permanent Scatterers technique. In the current project, standard processing was performed on two independent series of radar images covering the Trondheim region. By processing two sets of images, we obtained two independent datasets that could be compared at a regional and local scale. The pattern of subsidence is identical where the datasets overlap. It is proposed that a more detailed processing be carried out over a smaller area of interes. This will result in an increased data density as well as more accurate velocity field. Future monitoring will be possible with the use of images from the Radarset 1 and 2 satellites.