Spectrally segmented principal component analysis of hyperspectral imagery for mapping invasive plant species

Principal component analysis (PCA) is one of the most commonly adopted feature reduction techniques in remote sensing image analysis. However, it may overlook subtle but useful information if directly applied to the analysis of hyperspectral data, especially for the discrimination among different vegetation types. In order to accurately map an invasive plant species (horse tamarind, Leucaena leucocephala) in southern Taiwan using Hyperion hyperspectral imagery, this study developed a spectrally segmented principal component analysis based on spectral characteristics of vegetation over different wavelength regions. The developed algorithm can not only reduce the dimensionality of hyperspectral imagery but also extract helpful information for differentiating the target plant species from other vegetation types more effectively. Experiments conducted in this study demonstrated that the developed algorithm performs better than correlation-based segmented principal component transformation (SPCT) and conventional PCA (Overall Accuracy: 86%, 76%, 66%; Kappa value: 0.81, 0.69, 0.57) in detecting the target plant species as well as mapping other vegetation covers.