A Novel Multiband Fusion Method Based on a Modified RELAX Algorithm for High-Resolution and Anti-Non-Gaussian Colored Clutter Microwave Imaging

A novel multiband fusion method based on a modified RELAX algorithm (MRA) is proposed. In the MRA, a maximum difference criterion is applied to the singular values of echoes' Hankel matrix to improve the accuracy of calculating the number of scattering centers. In addition, a transformation process is put forward to merge the frequency-dependent factor (FDF) term, which is in the geometrical theory of diffraction (GTD) model, into the phase term of the echo to simplify the model. Moreover, a matching relationship for the correspondence between the FDF values and the cost function is established to effectively increase the estimated precision of the FDF. Therefore, based on the MRA, exact estimations of the incoherent errors among subband echoes are achieved, and then a fused full-band echo (FBE) with high estimation accuracy is produced. Using all the fused FBEes, high-resolution, anti-non-Gaussian colored clutter microwave imaging is realized. The effectiveness of the proposed method is validated with the simulated and real-data experimental results in a simulated non-Gaussian colored clutter environment.