Sub-pixel mapping of land cover using sub-pixel swapping algorithm and topographic data
YU Zhoulu1, WANG Wenchao2, RONG Yi2, SHEN Zhangquan1
1. College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; 2. Hangzhou Federation of Land Planning and Design Consulting Co. Ltd., Hangzhou 310030, China
Abstract：When remote sensing images are used to provide information for land cover mapping, it is negatively affected by the occurrence of mixed pixels in the remote sensing images, particularly in the case of coarse spatial resolutions. Soft classification and super-resolution(sub-pixel) mapping techniques can solve this kind of problems. The pixel-swapping(PS)algorithm is a simple and efficient technique for sub-pixel mapping. However, its computation is inefficient and yields poor mapping accuracy when the super-resolution scale factor (S)is large. A possible reason for this is that it only relies on the information from the fraction images. In this study, the digital elevation model(DEM) and their derivative data are employed as supplementary information for the PS algorithm so as to improve super-resolution mapping accuracy. Some conclusions have been reached: ① The sub-pixel mapping accuracy could be improved with the assistance of the DEM even if the scale factor is large; ② The mapping accuracy by incorporating both elevation and slope information is better than that of using elevation or slope data alone; ③ Mapping accuracy is less sensitive to the number of neighbors when scale factor is large;④ The computing efficiency is improved when incorporating DEM in pixel-swapping. Thus, it is feasible to use DEM as supplemental information for sub-pixel mapping.
虞舟鲁, 王文超, 戎奕, 沈掌泉. 基于子像元交换算法和地形数据的土地覆盖亚像元制图研究[J]. 国土资源遥感, 2017, 29(4): 88-97.
YU Zhoulu, WANG Wenchao, RONG Yi, SHEN Zhangquan. Sub-pixel mapping of land cover using sub-pixel swapping algorithm and topographic data. REMOTE SENSING FOR LAND & RESOURCES, 2017, 29(4): 88-97.
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2017, Vol. 29 
