This award funds research to develop methods of remotely detecting small deformations of the ground surface and civil infrastructure. Natural and constructed geotechnical facilities, such as dams, retaining structures, and earthen slopes, are vital components of civil infrastructure. Monitoring movements and deformations of geotechnical facilities is important for ensuring acceptable engineering performance and identifying potential hazards to the public. Ideally, problems should be detected at an early stage when the movements are both small in magnitude and localized in area. In practice, this can be challenging due to the massive size of geotechnical facilities and the limitations of current deformation monitoring technology. This research will focus on application and enhancement of an emerging remote sensing technology "ground-based interferometric radar" for detecting and measuring small and localized deformations of geotechnical facilities. The ultimate goal of this research is to develop and improve technology that can be used to better understand the performance of civil infrastructure, detect problems at an early stage of development, and mitigate the effects of natural hazards on society.
Ground-based interferometric radar is an emerging active-source, scanning technique that has the potential to fill a gap in deformation measurement capabilities for geotechnical engineering applications. Past studies of ground-based interferometric radar have focused on measuring large spatial-scale surface movements (e.g. landslides) where the surface area of interest may be tens of thousands of square meters and cover thousands of radar ground pixels. This study will focus on the application of ground-based interferometric radar for detecting small (sub-mm) and localized (a few m2) movements where the region of movement may be pixel scale or smaller in size. The conventional approach to collecting and processing interferometric radar data (developed for satellite-based studies) was not designed and optimized for these applications. There are no in-depth studies of ground-based interferometric radar for detecting small and localized deformations. Unique existing data sets will be used in conjunction with data collected from this project to meet the following objectives: (1) identify effective data collection and processing procedures for detecting and measuring sub-pixel to pixel scale surface movements using ground-based interferometric radar, (2) use controlled studies to quantify the accuracy and uncertainties in ground-based interferometric radar deformation measurements of sub-pixel to pixel scale surface movements, and (3) study methods to model and mitigate atmospheric effects and other noise. Successful completion of the project objectives will result in advancement of the state of knowledge regarding the application of ground-based interferometric radar for measuring deformations of the ground surface and civil infrastructure.
