  Recent constellations of satellites, including the Skysat constellation, are
able to acquire bursts of images. This new acquisition mode allows for modern
image restoration techniques, including multi-frame super-resolution. As the
satellite moves during the acquisition of the burst, elevation changes in the
scene translate into noticeable parallax. This parallax hinders the results of
the restoration. To cope with this issue, we propose a novel parallax
estimation method. The method is composed of a linear Plane+Parallax
decomposition of the apparent motion and a multi-frame optical flow algorithm
that exploits all frames simultaneously. Using SkySat L1A images, we show that
the estimated per-pixel displacements are important for applying multi-frame
super-resolution on scenes containing elevation changes and that can also be
used to estimate a coarse 3D surface model.
