Abundance Estimation Based on Band Fusion and Prioritization Mechanism

To achieve real-time abundance estimation of hyperspectral images and improve the accuracy and efficiency of estimation, this article proposes a new band processing approach for abundance estimation, to be called sequential band fusion (SBF). To achieve SBF, a new band priority mechanism is proposed. It is derived from the concept of orthogonal subspace projection (OSP) by orthogonalizing undesired targets using projection while minimizing the variance resulting from the background. By taking advantage of OSP, the interfering effects caused by all undesired targets can be eliminated, and then, the detector produced by a target of interest can be further used as a measure of prioritizing bands as well as a means of searching bands for this particular target. As a result, two ranking-based band priority criteria (RP), called maximum OSP-based RP (MaxOSP-RP) and minimum OSP-based RP (MinOSP-RP), and two searching-based band priority criteria (SP), called sequential feedforward band search (SFBS) and sequential backward band search (SBBS), can be derived. We provide a detailed theoretical description and formula derivation of the SBF and combine it with band sequence (BSQ), RP, and SP to propose three different fusion mechanisms: SBF based on BSQ (SBF-BSQ), SBF based on RP (SBF-RP), and SBF with SP (SBF-SP) to make the fusion mechanism applied to different scenarios. Experimental results show that the proposed methods perform well for abundance estimation.