Microvibration Modes Reconstruction Based on Micro-Doppler Coincidence Imaging

Microvibration, a ubiquitous nature phenomenon, can be seen as a characteristic feature on the objects, and these vibrations always have tiny amplitudes which are much less than the wavelengths of the sensing systems, and thus these motions information can only be reflected in the phase item of echo. Normally, the conventional radar system can detect these microvibrations through time–frequency analysis, but these vibration characteristics can only be reflected by the time–frequency spectrum, and the spatial distribution of these microvibrations cannot be reconstructed precisely. Ghost imaging (GI), a novel imaging method also known as coincidence imaging that originated in the quantum and optical fields, can reconstruct unknown images using computational methods. To reconstruct the spatial distribution of microvibrations, this article proposes a new method based on a coincidence imaging system. A detailed model of target microvibration is created first, taking into account two categories: discrete and continuous targets. We use the first-order field correlation feature to obtain objective different microvibration distribution based on the complex target models and time–frequency analysis in this work.