L-Band InSAR Ground Movement Monitoring of Midstream Assets in the Appalachian Region
Proceedings Publication Date
The United States Geological Survey (USGS) classifies almost all of the Appalachian region of the USA as having “High Landslide Susceptibility” and “High Landslide Incidence” due to the area’s geology, topography, and high precipitation (Figure 1) . The area is also home to significant oil & gas assets, including reservoirs, well sites, gathering lines, and high-pressure natural gas transmission pipelines. Landslides across the Appalachian region have caused pipelines to rupture and explode, risking loss of life and property and releasing large amounts of methane into the atmosphere. Determining the location and severity of active geohazards across this large region is not easy nor economical with traditional monitoring techniques and ground instrumentation. Satellite-based remote sensing technologies such as InSAR provide the ability to map contemporary landslides and identify specific locations of risk across vast pipeline networks spanning this region. In addition to analysing historical radar imagery of this region from several satellites, 3v Geomatics (3vG) has been tasking the Japan Aerospace Exploration Agency’s (JAXA) ALOS-2 satellite to acquire new radar satellite images across the Appalachian highlands since July 2018. The ALOS-2 satellite was chosen because its long-wavelength (L-band) sensor is uniquely capable of penetrating the dense vegetation (Guthrie et al, 2018). InSAR analyzes changes in phase information between radar satellite images to measure displacement with millimeter precision (using X band) to centimeter precision (using L-band such as ALOS-2). The frequency of measurements depends on the satellite revisit period, which is 14 days for ALOS-2. 3vG is monitoring 10 regularly imaged ALOS-2 footprints across the Appalachian highlands, covering 28,000 square kilometers (10,810 square miles), on behalf of North America’s largest midstream oil & gas operators (Figure 2) . Results are delivered after each new image acquisition to provide actionable intelligence, informing operators when and where landslides could jeopardize the integrity of their assets.