Analysis of spectral signatures of urban surfaces for their identification using hyperspectral HyMap data

Abstract

In this study a spectral library was developed, which forms the database for an area-wide identification of urban surface materials using hyperspectral HyMap data. Spectra are measured with a field spectrometer in the wavelength range between 0.35-2.5 /spl mu/m in 2151 channels. For the systematic assessment of materials the urban surface is categorized in regard to its degree of surface sealing resulting in urban surface cover types. These resulting categories form the thematic frame for the assessment of urban surface materials. The presented surface materials of the sealed category belong to e.g. the ceramic/mineral group, metallic or synthetic group. They are analyzed in regard to variations in color or manufacturing types. Non-sealed surfaces, such as soil, or vegetation are investigated in regard to their urban characteristics. The obtained spectral library is used to explore the spectral information content of hyperspectral HyMap data of Dresden, Germany. For an area-wide identification of urban surface materials, a combined classification and unmixing approach was applied leading to a precise identification of surface materials. Thereby, this technique benefits from the extracted knowledge about the spectral characteristics of urban surface materials.