The Information technology for building a seamless multi-temporal mosaic from radar space images

Abstract

One of the most important factors influencing the planet as a whole and the continent in particular is the processes of destruction of the Antarctic ice sheets. Remote sensing images have become an important means of information acquisition. Visualization of several radar mosaics for different time substantially enhances observation of the ice sheets by showing dynamics of development of cracks, motion of icebergs, directions of streams near the surface of water along the coastline and dynamics of the ice field. This work presents the information technology of building a seamless imagery mosaic coverage of satellite radar scenes. The data under consideration are level-1 ground range detected Sentinel-1 products with dualpolarisation. Since not in all Path/Frame combinations scenes had two polarizations, HH and HV, polarization HH was chosen as the main one. As the direction of imaging, both ascending and descending scenes were chosen. For decreasing the volume of computations, scenes for the mosaic of Antarctica resampled to the spatial resolution of 120 meters and presented in the WGS-84 / Antarctic Polar Stereographic projection. 71% of the created coverage of Antarctica, when scenes are cyclically changed, reflects the changes in time of the coastline of the continent well. The key points related to the technology of preparation of the Sentinel-1 scenes for building the mosaic are presented. The first scene in each pair, save for the first pair, is a mosaic in itself. The method of stitching of the scenes into a mosaic is based on the process of geometric analysis of location of pixels overlapping in the scenes. The main results are shown in a fragment of the mosaic coverage of Antarctica. Experiments show that the technology can achieve automatic panoramic mosaic of the survey area.