I am new to Landsat images processing, and I'm trying to create land cover change maps over an area covering around 15 landsat scenes.
I downloaded all scenes available, unfortunately some layers don't align perfectly over time, even having same path and row, and same coordinate system (UTM22N). At first, I just deleted the misaligned scenes, because I had enough images available to get a correct cloud free map for each year I wanted.
But in a few cases (p227r057, p227r058 for example, but from what I've seen until now, I'm facing the problem for probably half of the landsat locations), I cannot find more that 2 or 3 correctly aligned images over more than 20 layers. It is probably just a vertical and horizontal shift, but the problem is that this shift is not constant in distance (from a few tens of meters to a few kilometers) and in direction.
Is there an easy way to cope with that problem, or is it necessary to proceed to the orthorectification of all (a few hundreds scenes multiplied by the number of bands) images?
I'm working with GRASS GIS.