Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XL-7/W3, 721-728, 2015
© Author(s) 2015. This work is distributed
under the Creative Commons Attribution 3.0 License.
29 Apr 2015
Topographic Correction Module at Storm (TC@Storm)
K. Zakšek1, K. Čotar2, T. Veljanovski3, P. Pehani3, and K. Oštir2,3 1Inst. of Geophysics, Uni. Hamburg, Hamburg, Germany
2Slovenian Centre of Excellence for Space Sciences and Technologies Space-SI, Ljubljana, Slovenia
3Research Centre of the Slovenian Academy of Sciences and Arts, Ljubljana, Slovenia
Keywords: Topographic Correction, Complex Terrain, Shadow Detection, Solar Irradiance, Sky-view Factor, Validation Abstract. Different solar position in combination with terrain slope and aspect result in different illumination of inclined surfaces. Therefore, the retrieved satellite data cannot be accurately transformed to the spectral reflectance, which depends only on the land cover. The topographic correction should remove this effect and enable further automatic processing of higher level products. The topographic correction TC@STORM was developed as a module within the SPACE-SI automatic near-real-time image processing chain STORM. It combines physical approach with the standard Minnaert method. The total irradiance is modelled as a three-component irradiance: direct (dependent on incidence angle, sun zenith angle and slope), diffuse from the sky (dependent mainly on sky-view factor), and diffuse reflected from the terrain (dependent on sky-view factor and albedo). For computation of diffuse irradiation from the sky we assume an anisotropic brightness of the sky. We iteratively estimate a linear combination from 10 different models, to provide the best results. Dependent on the data resolution, we mask shades based on radiometric (image) or geometric properties. The method was tested on RapidEye, Landsat 8, and PROBA-V data. Final results of the correction were evaluated and statistically validated based on various topography settings and land cover classes. Images show great improvements in shaded areas.
Conference paper (PDF, 3568 KB)

Citation: Zakšek, K., Čotar, K., Veljanovski, T., Pehani, P., and Oštir, K.: Topographic Correction Module at Storm (TC@Storm), Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XL-7/W3, 721-728, doi:10.5194/isprsarchives-XL-7-W3-721-2015, 2015.

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