Publications

Zhang, X; Liu, LY; Wang, YJ; Hu, Y; Zhang, B (2018). A SPECLib-based operational classification approach: A preliminary test on China land cover mapping at 30 m. INTERNATIONAL JOURNAL OF APPLIED EARTH OBSERVATION AND GEOINFORMATION, 71, 83-94.

Abstract
Fine-resolution land cover mapping at the regional or global scale is usually time-consuming and involves a lot of manual participation. This article proposes a novel and automatic land cover mapping approach called the SPatial-tEmporal speCtral Library (SPECLib), which can produce a land cover map with a 30-m spatial resolution. First, the SPECLib is developed by extracting reference spectra for uniform, typical samples of each land cover type by combining the GlobCover2009 land cover product and the 8-day composite MODIS Surface Reflectance Product (MODO9 A1). SPECLib has a temporal resolution of 8 days and contains most of the land cover types in each 1.5 degrees x 1.5 degrees geographic cell. For an arbitrary temporal stage, for each geographical cell of the SPECLib, there are a total of about 5000 MODIS spectra. Secondly, an operational approach for automatic land cover mapping using Landsat data is developed based on SPECLib. For each Landsat scene to be classified, the reference spectra of the land cover types in the corresponding geographic cell were automatically extracted and normalized. The Landsat scene was then classified by using the normalized reference spectra from SPECLib in an integrated classification approach that combined MLC (Maximum Likelihood Classification) and SAM (Spectral Angle Mapper). Finally, the SPECLib-based approach is tested using 510 single-date Landsat 8 OLI scenes to produce a land cover map of China. The map was validated using 11,366 interpretation samples and was shown to have an overall accuracy of 77.34% and a kappa coefficient of 0.729. Therefore, the preliminary results indicate that the SPECLib-based operational classification approach is a promisingly automatic method for global land cover mapping at a resolution of 30 m.

DOI:
10.1016/j.jag.2018.05.006

ISSN:
0303-2434