Earthen Levee Monitoring with Synthetic Aperture Radar

Aanstoos, J.V., Hasan, K., O'Hara C., Prasad, S., Dabbiru, L., Mahrooghy, M., Gokaraju, B., Lee, M., & Nobrega, R. A. A. (2011). Earthen Levee Monitoring with Synthetic Aperture Radar. Proc. IEEE Applied Imagery Pattern Recognition Workshop. Washington, DC: IEEE.

Earthen Levee Monitoring with Synthetic Aperture Radar James V. Aanstoos1, Khaled Hasan1, Charles G. O’Hara1, Saurabh Prasad1, Lalitha Dabbiru1, Majid Mahrooghy2, Balakrishna Gokaraju1, Rodrigo Nobrega1 1Geosystems Research Institute, Mississippi State University, MS 39762, USA 2Department of Electrical Engineering, Mississippi State University, MS 39762, USA Contact: James Aanstoos aanstoos@gri.msstate.edu (662) 325-2647 Earthen levees protect large areas of populated and cultivated land in the US from flooding. The potential loss of life and property associated with the catastrophic failure of levees can be extremely large. Over the entire US, there are over 100,000 miles of levee structures of varying designs and conditions. Levee managers and federal agencies need to assess levee health rapidly with robust techniques that identify, classify and prioritize levee vulnerabilities with lower costs than traditional methods such as soil-boring programs. This paper gives an update with the latest results of an ongoing project studying the use of synthetic aperture radar (SAR) as an aid to the levee screening process. SAR sensors being utilized include: (1) The NASA UAVSAR (Uninhabited Aerial Vehicle SAR), a fully polarimetric L-band SAR which is specifically designed to acquire airborne repeat track SAR data for differential interferometric measurements. The instrument is capable of sub-meter ground sample distance. (2) The German TerraSAR-X space-based SAR platforms. This has spatial resolution approaching that of the airborne SAR and also has multi-polar options but uses a much shorter wavelength. Our test study area is a stretch of 230 km of levees along the lower Mississippi River. SAR interferometric mode is capable of identifying vertical displacements on the order of a few millimeters. The L-band measurements can penetrate soil to as much as one meter depth. Thus it is valuable in detecting changes in levees that will be key inputs to a levee vulnerability classification system. We report on the use of various feature detection algorithms being applied to the polarimetric and interferometric data, including entropy-anisotropy decomposition, wavelet transforms, and methods based on the Grey Level Co-occurrence Matrix (GLCM). The features detected are compared with various ground truth data including soil conductivity measurements, soil sample tests, and on site visual inspections. Radar data acquired over several dates before, during, and after the record floods of spring 2011 provided a valuable source of data for training and testing the classification algorithms; results with this data will be presented.