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Land cover mapping by optical remote sensing has many obstacles including clouds. Clouds block solar radiation coming to earth surface and reflective radiance from the earth surface to remote optical sensors resulting. Therefore, clouds result no-signal areas in images that cannot be used for study of ground objects. In many cases, thin clouds degrade quality of reflective radiance and some times alter, unexpectedly, spectral reflectance characteristics of ground objects leading to false classification. In this paper, the authors present an algorithm on application of multidate for development of cloud free image. The used image data were received in rainy and dry seasons and by stacking, cloud free images representing rainy and dry seasons were created. These cloud free images can be used further for classification of land cover in rainy and dry seasons. Experiments were conducted with Landsat 8 OLI images with path/row number 124/51 covering Dak Lak province of Vietnam. The results of case study were development of cloud free image data representing rainy and dry seasons allowing separation of evegreen and deciduous forests in the study site.
 Steve Foga, Pat L. Scaramuzza, Song Guo, Zhe Zhu, Ronald D.Dilley Jr, Tim Beckmann, Gail L. Schmidt, John L. Dwyer, M.Joseph Hughes, Brady Laue, Cloud detection algorithm comparison and validation for operational Landsat data products, Remote Sensing of Environment. 194 (2017) 379–390. https://doi.org/10.1016/j.rse.2017.03.026
 Chengquan Huang, Samuel N. Goward, Jeffrey G. Masek, Feng Gao, Eric F. Vermote, Nancy Thomas, Karen Schleeweis, Robert E. Kennedy, Zhiliang Zhu, Jeffery C. Eidenshink & John R.G. Townshend, Development of time series stacks of Landsat images for reconstructing forest disturbance history, International Journal of Digital Earth. 2 (2019) 195–218. https://doi.org/10.1080 /17538940902801614
 Nguyen Dinh Duong, Le Minh Hang, Tran Anh Tuan, Zutao Ouyang, Development of a spectral-pattern-analysis-based method for automated water body extraction using Landsat image data: A case study in central Vietnam and southern Laos, Limnology and Oceanography: Methods. 15 (2017) 945–959. https://doi.org/10.1002/lom3.10215
 N. D. Duong, Automated classification of Land cover using Landsat 8 OLI Surface Reflectance product and spectral pattern analysis concept - Case study in Hanoi, Vietnam, Int. Arch. Photogramm. Remote Sens. Spat. Inf. Sci. XLI-B8 (2016) 987–991. https://doi.org/10.5194/isprs-archives-XLI-B8-987-2016
 Portal DakLak Provincial, Natural conditions. https://daklak.gov.vn/-/i-ieu-kien-tu-nhien (in Vietnamese, accessed 10 August 2019).
 EarthExplorer - Home, U.S. Geological Survey (USGS). https://earthexplorer.usgs.gov/ (accessed 2 August 2019).
 U.S. Geological Survey, Landsat Collection 1 Level-1 Quality Assessment Band. https://www. usgs.gov/land-resources/nli/landsat/landsat-collection-1-level-1-quality-assessment-band?qt-science_support_page_related_con=0#qt-science_support_page_related_con (accessed 10 August 2019).
 U.S. Geological Survey, Landsat 8 Data Users Handbook, Version 4.0, April 2019, pp. 55-56. https://www.usgs.gov/land-resources/nli/landsat/ landsat-8-data-users-handbook (accessed 10 August 2019).