PR-420-133721-R01 Comparison of Radar Satellite Methods for Observation of Stability

Abstract

This report discusses the use of Synthetic Aperture Radar (SAR) satellites for monitoring above ground pipelines and buried pipeline Rights-Of-Way (ROWs) using Interferometric Synthetic Aperture Radar (InSAR) techniques. The main thrust of the research was to evaluate the suitability of above-ground pipeline support members as InSAR measurement points, and to adapt existing techniques to allow for precise monitoring of jacking and subsidence caused by permafrost degradation and dynamics. The study site at Prudhoe Bay, Alaska includes more than 60,000 horizontal pipeline supports. The known locations of supports were used to identify and isolate supports in the radar imagery, and the phase and intensity of supports were analyzed to determine their ability to provide reliable estimates of deformation. An additional component of this research was the comparison of two satellites operating at different frequencies, RADARSAT-2 operating at C-band and TerraSAR-X operating at X-band. One year of data was acquired with both sensors in similar acquisition geometries and resolutions, at 24-day intervals for RADARSAT-2 and 11-day intervals for TerraSAR-X. Recommendations are made on the choice of wavelength and concerning future work in this area. A list of technical requirements is also provided. The technologies for obtaining ground deformation estimates from natural targets, coherent targets and homogeneous and distributed targets are explained and supported by three operational case-studies in different environments. The work should provide above-ground pipeline operators working in permafrost areas with a clear view of the current state of research towards the operationalization of InSAR monitoring, but also of current operational capabilities in other pipeline applications, including ROW geohazard monitoring and monitoring of buried pipelines crossing Enhanced Oil Recovery (EOR) fields.