A tight multiframe registration problem with application to Earth observation satellite design

Image registration can play a key role to increase the SNR of Earth satellite images by fusing many successive noisy thin image stripes in real time, before transmitting to the ground the final fused image. Yet these stripes cannot be fused directly by addition because their position is altered by microvibrations and other geometric perturbations. These must be compensated using limited onboard computational resources with high subpixel accuracy and in real time. In this paper we study the fundamental performance limits for this problem and propose a real time solution that nonetheless gets close to the theoretical limits. We introduce a scheme using temporal convolution together with online noise estimation, optical flow and a non-conventional multiframe method for measuring global translation. Finally, we compare our results with the theoretical bounds and other state-of-the-art methods. The results are conclusive on the fronts of accuracy and complexity.