Diffraction imaging using a mathematical morphological filter with a time-varying structuring element

Abstract

Diffraction imaging is an important technique for high-resolution imaging because of the close relationship between diffractions and small-scale discontinuities. Therefore, we we have developed a diffraction imaging method using a mathematical morphological filter (MMF). In a common image gather, reflections have an evident energy band associated with the Fresnel zone and stationary point, whereas diffractions can be observed in a wide illumination direction and therefore have no energy band. Based on these phenomena, we analyze the amplitude distributions of the diffractions and reflections and develop a time-varying structuring element (SE) in the MMF. Based on the time-varying SE, our method can effectively suppress reflections and has the advantage of automatically preserving the diffractions energy near the stationary point. Numerical and field experiments demonstrate the efficient performance of the proposed method in imaging diffractions and obtaining high-resolution information.