Application of fusion in satellite images the Landsat-8 and Sentinel-2 in environmental monitoring

In order to increase the spectral and spatial resolution of satellite images, the fusion of multi-resolution images can be used, however, the image fusion usually introduces some spectral and spatial distortions in the resulting fused image that the amount of these distortions highly depends on the pan sharpening technique as well as the type of data. The aim of this study is the fusion of Landsat 8 Operational Land Imager (OLI) with the date of 8 January 2018, and Sentinel-2 Multispectral Imager (MSI) with the date of 11 January 2018, using the Gram Schmidt, CN, Brovey, DWT, SFIM, Multiplication methods in the Ahvaz city. In order to evaluate the image quality that fussed, CC, SAM, PSNR, SIMM, and Laplacian indices were used. The results showed among the used methods, DWT and Brovey, have the best results from the spectral and spatial aspect, respectively. Also, the highest spatial distortion with the amount of 1.18 in the SAM index was in the Multiplication method and the maximum spatial deviation in the DWT index with a correlation of 0.47 with the reference image. Multiplication and DWT methods have the most spatially and spectrally distortion. Therefore, the results showed that SFIM is the optimum method of spectral and spatial aspects.