1. Polarimetric SAR remote sensing of the 2011 Tohoku earthquake using ALOS/PALSAR
- Author
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Sang-Eun Park, Yoshio Yamaguchi, and Duk-jin Kim
- Subjects
Synthetic aperture radar ,Markov random field ,Polarimetry ,Soil Science ,Magnitude (mathematics) ,Geology ,Thresholding ,law.invention ,law ,Remote sensing (archaeology) ,Environmental science ,Computers in Earth Sciences ,Radar ,Change detection ,Remote sensing - Abstract
The 2011 magnitude 9.0 Tohoku earthquake caused catastrophic damage to coastal areas in northeastern Japan. It is quite difficult to obtain an immediate assessment of large-scale natural disasters by ground survey. Microwave remote sensing by airborne or spaceborne sensors is a suitable tool for monitoring near-real-time damage over large areas. However, it is not always possible to acquire datasets with sufficient spatial and temporal resolutions for the precise detection of large areas of damage; therefore, this study focuses on the application of fully polarimetric scattering observations for deduction of information about damaged areas. Earthquake-induced changes in the radar backscattering mechanism are investigated by polarimetric scattering mechanism indicators. In addition, a change detection technique using the Expectation–Maximization (EM) based thresholding approach is applied to various polarimetric features. Furthermore, a new polarimetric information fusion method based on the contextual Markov Random Field (MRF) is proposed. The mapping accuracy for tsunami-swept urban areas can be improved by about 50% with significant reduction of false- and missed-alarm rates compared with the single-polarization SAR approach.
- Published
- 2013