A Novel Multiband Fusion Method Considering Scattering Characteristic Fluctuation Between Sub-Bands

Multiband fusion (MF) technology can generate an ultra-wideband echo (UWBE) from multiple sub-band echoes (SBEs), thereby improving radar range resolution and enhancing target recognition capabilities. However, current MF methods generally do not account for the incoherence introduced by fluctuations in the scattering characteristics of scattering centers (SCs) across different frequency bands. This oversight can lead to degraded fusion performance. To address this limitation, a novel MF method that explicitly considers the fluctuation of SC characteristics between sub-bands is proposed in this paper. Firstly, a theoretical analysis of the additional incoherent phase term introduced by these fluctuations is conducted, which demonstrates its impact on fusion accuracy. Based on this analysis, scattering centers are extracted from SBEs based on the geometrical theory of diffraction (GTD) model, and then categorized into two distinct types: intrinsic scattering centers (ISCs) and unique scattering centers (USCs). Subsequently, a new incoherent phase estimation and compensation method is proposed, leveraging this categorization to effectively mitigate the inter-sub-band incoherence. The two types of SCs are then processed through either fusion or super-resolution to generate individual UWBEs, which are finally combined to form the final UWBE. The effectiveness of the proposed method is validated using both simulated electromagnetic scattering data and static measured data. Numerical results demonstrate that the proposed method achieves significantly greater fusion accuracy compared to traditional MF approaches, confirming the practical benefits of incorporating SC fluctuation modeling into the fusion process.