Single Baseline 3-D Structure Retrieval Using Radar with Wide Fractional Bandwidth Mounted on Drones

Abstract:
Synthetic aperture radar (SAR) interferometry (InSAR) provides accurate topographic information of an area by using of a pair of SAR images. However, ambiguities arise in the case of volumetric media where multiple scattering occur in a single resolution cell. Polarimetry-based methods assume orthogonal and deterministic scattering mechanisms to resolve the ambiguity and obtain three-dimensional structure of the volume. SAR tomography use additional measurements which require numerous observations. An alternative approach is to use signals with wide fractional bandwidth and obtain the InSAR coherence over a wide range of vertical wavenumber with a single baseline. Signals with a wide fractional bandwidth is available from radars mounted on drones, which is a promising platform for local and frequent SAR remote sensing. A method to simulate radar data backscattered from semi-transparent media and the coherence estimation over a wide vertical wavenumber using a single baseline is presented. The coherence estimated from the simulated data can be used to demonstrate the single-baseline three-dimensional inversion method.