Digital elevation model in southwestern desert of Iraq using interferometry method from Sentinel-1A images

Abstract

One of the essential goals of remote sensing applications is to create a highly accurate digital elevation model. Synthetic aperture radar Interferometry (InSAR) is a popular three-dimensional imaging technique for creating a Digital Elevation Model (DEM). The phase difference between the complex SAR images creates an interference fringe pattern that may be used to calculate the elevation of any point on the observed landscape. The use of traditional methods for creating DEMs and drawing terrain maps, which require Costly and time-consuming, has clearly affected the creation and updating of terrain maps in Iraq. This study aims to use InSAR technology to easily create accurate DEMs that contribute to the generation and updating of terrain maps periodically. In this study, the synthetic aperture radar interferometry approach was used on the interference stack generated from a pair of Sentinel-1A images to generate a DEM and a terrain map of the desert region in south-western Iraq. The elevations of the digital elevation model were compared with those of the RTK-GCPs in the region of interest. The results obtained from this study is a terrain map with the contour lines generated from the digital elevation model created by the InSAR technique with an accuracy of 18 m with the root mean square error (RMSE) of the DEM was 8.17, and The Mean Absolute Error (MAE) is 8.31. The results were analysed using F-Test, T-Test, and Chi-Square Tests, and the results of the statistical analysis showed that there are no significant variances in the levels of the errors between the values of RTK-GCPs and the values of elevations of the generated digital elevation model. The output proves the authenticity with the precision of the used Sentinel-1 image for synthetic aperture radar interferometry technique to DEM generation which is of great importance for the knowledge of terrain features and for accurate terrain mapping with a short time compared to the old traditional methods.