Based on the correlation diagram between the master and slave images (Fig. 5), the pair of appropriate images in terms of the shortest spatial and temporal lines is identified to produce the interferogram. As shown in Fig. 5, the maximum vertical baseline is obtained between -400 and -400. The obtained interferograms indicate the cumulative phase of the study area, which fluctuates between zero and 2ᴫ. Using StaMPS method on interferograms, 650 points were identified and selected as permanent scatter points in the study area. As can be seen in Figure 7, the cumulative displacement of the permanent dispersant points varies from + 45 mm to -45 mm. The displacements occur in the direction of the satellitechr('39')s view so that the positive numbers Indicates surface approach to satellite and the uplift and the negative numbers indicate the surfacechr('39')s distance from the satellite and the subsidence. As shown in the figure, in the western part of the mine wall, areas of 100,000 square meters have been heavily subsided. The next area, which has high subsidence points, is in the eastern part of the mine wall with an area of 68,000 square meters. The third area is located in the northwestern part of the mine with an area of 17,000 square meters.
By measuring the amount of displacement of Persist Scatters points, the altitude changes occurred in the mining area. Based on the results, the altitude variation changes in the range of 45 mm to -45 mm per year. Accordingly, 3 subsidence area were identified in western, eastern and northwestern parts of the mine wall with an area of 100, 68, and 17 thousand square meters. Considering the importance of the subject and in order to prevent the destruction of the mine wall, more precise geotechnical studies are needed in these specified areas.
