An automated multisensor satellite imagery registration technique based on the optimization of contour features
Spatial registration of multidate or multisensor images is required for many applications in remote sensing. Automatic image registration, which has been extensively studied in other areas of image processing, is still a complex problem in the framework of remote sensing. This work explores an alternative strategy for a fully automatic and operational registration system capable of registering multitemporal and multisensor remote sensing satellite images with high accuracy and avoiding the use of ground control points, exploiting the maximum reliable information in both images (coastlines not occluded by clouds). The automatic feature-based approach is summarized as follows: (i) reference image coastline extraction; (ii) sensed image gradient energy map estimation and (iii) contour matching, mapping function estimation and transformation of the sensed images. Several experimental results for single sensor imagery (AVHRR/3) and multisensor imagery (AVHRR/3-SeaWiFS-MODIS-ATSR) from different viewpoints and dates have verified the robustness and accuracy of the proposed automatic registration algorithm, demonstrating its capability of registering satellite images of coastal areas within one pixel.