90° yaw imaging AHS AVIRIS Africa Dunhuang site Gram–Schmidt orthogonalization History of engineering & technology HyMap KSVD Otsu’s method SVM Technology: general issues adaptive window agroforestry airborne laser scanning algebraic multigrid methods anomaly detection band expansion process (BEP) band grouping band selection band selection (BS) band subset selection (BSS) biodiversity class imbalance classification composite kernel constrained energy minimization constrained energy minimization (CEM) correlation band expansion process (CBEP) data fusion