The main objective of this study was to evaluate the prediction of SRTM30 from the freely available SRTM90 by using means of different interpolation orders. In this study three sorts of data were used, actual data of SRTM30 of USA which were used as simulated data, SRTM90 data which were used as a real data whereas no idea bout SRTM30 are available and ground-truth data that were used for the verification of the predicted SRTM30. SRTM90 data used in this study was concerned with part area of Egypt extended from 29º N and 32º E to 30º N and 33º E which have all features of terrain surface. The ground truth data were used within the same study area of SRTM90 to examine and analyze the characteristics of the interpolation. The interpolation used in this study is polynomial with different types of orders. The results obtained indicated an improvement in the prediction of SRTM30. However, these results cannot
be approved completely, whereas interpolation was just a foresight procedure, at least it was helpful to improve the terrain surface or DEM produced from SRTM90