Fractional snow cover estimation in complex alpine-forested environments using an artificial neural network
Fractional snow cover estimation in complex alpine-forested environments using an artificial neural network
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DOI:
10.1016/j.rse.2014.09.026
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发表时间:
2015-01-01
影响因子:
13.5
通讯作者:
Wisniewski, Wit T.
中科院分区:
文献类型:
--
作者:
Czyzowska-Wisniewski, Elzbieta H.;van Leeuwen, Willem J. D.;Wisniewski, Wit T.
There is an undisputed need to increase accuracy of Fractional Snow Cover (FSC) estimation in regions of complex terrain, especially in areas dependent on winter snow accumulation for a substantial portion of their water supply, such as the western United States. The main aim of this research is to develop FSC estimation in complex alpine-forested environments using an Artificial Neural Network (ANN) methodology as a fusion framework between multi-sensor remotely sensed data at medium temporal/spatial resolution (e.g.16-day revisit time; 30 m; Landsat), and high spatial resolutions (e.g.1 m; IKONOS). This research is the first known attempt to develop a multi-scale estimator of FSC from surface equivalent reference data derived from IKONOS multispectral data. It is also the first endeavor to estimate FSC values by combining terrain and snow/non-snow reflectance data. The plasticity of the developed ANN Landsat-FSC model accommodates alpine-forest heterogeneity, and renders unbiased, comprehensive, and precise FSC estimates. The accuracy of the ANN Landsat based FSC is characterized by: (1) very low error values (mean error similar to 0.0002; RMSE similar to 0.10; MAE similar to 0.08 FSC), (2) high correlation with the ground equivalent reference datasets derived from I m resolution IKONOS images (r(2) similar to 0.9), and (3) robust FSC estimation that is independent of terrain/vegetation alpine heterogeneity. The latter is supported by a spatially uniform distribution of errors, and lack of correlation between terrain (slope, aspect, terrain shadow distribution), Normalized Difference Vegetation Index, and the error (r(2) = 0). (C) 2014 Elsevier Inc. All rights reserved.