Furthermore, different variables were produced by using the backscattering values obtained from the sample plots using VH and VV images. In addition, the backscattering values were calculated from the Sentinel-1 satellite image according to the VV and VH polarizations for each sample plot. Using the reflectance values obtained for each band, the values of vegetation indices in Table 8.1 were calculated for each sample plot. Reflectance values for 10 bands of the Sentinel-2 satellite image for each sample plot were obtained. The buffer was overlaid with the sample plots and satellite images with Geographical Information Systems (GIS).
According to the size of the sample plots, each sample plot was buffered as much as the radius length (e.g., for 400 m 2: 11.28 m for 600 m 2: 13.82, and for 800 m 2: 15.96 m). All preprocessing in the Sentinel-2 image was applied in the ENVI software. The satellite image was cut and made ready for analysis, taking into account the boundary of the research area. Also, the Sentinel-2 image Level-1C provides the top of the atmosphere reflectance. It was downloaded as Level-1C, which includes radiometric and geometric correction on a UTM, Zone 36 WGS84 projection. Ten spectral bands (Band 2-8, Band 8A, and Band 11-12) from the Sentinel-2 satellite image were used in this study. The satellite data were cut and made ready for analysis, taking into account the boundary of the research area. All preprocessing in the Sentinel-1 image was applied in the SNAP software. Then, the raw digital number values were converted to backscattering values (dB). The Doppler terrain correction with a digital elevation model (30 m) to the terrain correction was applied. The Lee Sigma filter (5 × 5) applied to the image. The terrain and radiometric calibration, and speckle filter were performed to a Sentinel-1 image.
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