Synchronizing Spatiotemporal Reflectance Fusion via Dual Bayesian Nonparametric Inference and Explicit Downsampling

Remote sensing images from a single sensor restrict in terms of spatial resolution and temporal resolution and they cannot simultaneously achieve high-precision and high-frequency synchronous observations. This paper proposes a spatiotemporal reflectance fusion method using double Bayesian nonparametric inferences for coupled feature space. Overcoming the limitations of existing fusion models, our approach incorporates downsampling, establishes a coupled feature space fusion model, and introduces a Beta-Bernoulli process to learn specific dictionaries. A dictionary atomic indicator ensures precise sparse projection relationships between coupled feature spaces. To address resolution disparities, a two-step Bayesian nonparametric fusion framework is employed. Experimental results demonstrate superior fusion performance, particularly in capturing surface reflectance changes in images depicting phenology or land-cover type changes. This method offers a promising solution to balance spatial and temporal resolutions, enhancing dynamic ecosystem monitoring and phenological parameter inversion.