Microwave Imaging of Weakly Reflective Vibrating Targets With Static Interference Suppression

Microwave-based vibration measurement methods are widely used in applications such as vital sign monitoring, remote active acoustic sensing, and structural health monitoring. However, detecting and imaging vibrating targets in cluttered environments remains a significant challenge, particularly for weakly reflective targets or in the presence of strong static interference. This work addresses these challenges by developing an effective imaging method for such targets. We propose the weakly reflective vibrating target imaging (WRVI) method that employs long-time coherent integration with phase compensation to enhance the imaging quality of weakly reflective vibrating targets and leverages the orthogonality of vibration signals at different frequencies to suppress static interference and mitigate occlusion caused by spectral leakage. An efficient implementation strategy is also developed to reduce computational complexity. Simulations and experimental results validate the method’s capability to distinguish weak targets obscured by noise and clutter and successfully demonstrate its effectiveness in localizing human subjects in complex environments.