Hyperspectral derivatives analysis for intertidal habitat mapping

摘要

Analysis of coastal marine algae communities enables an estimation of the state of coastal marine environments and provides evidence for environmental changes. Hyperspectral remote sensing provides a tool for mapping macroalgal habitats if the algal communities are spectrally resolvable. We tested the performance of a new approach for determining the distribution of macroalgae communities in the rocky intertidal zone of Helgoland (Germany) using airborne hyperspectral (AISA_(eagle)) data. This new approach calculates the slopes in wavelength regions between specific pigment absorption features and does not rely on absolute reflectance values. The first order derivatives of these wavelength regions form slope bands, which are then classified using a k-Means approach. The new derivatives approach proved to be a time effective possibility for identifying the dominating macroalgae species with sufficient accuracy (Cohan's kappa = 0.70). The method was tested on another AISA data set and turned out to be as a robust (Cohan's kappa = 0.77) and easy-to-use approach for delineating dominant algae communities or habitats, which can be adapted easily to different data sets.