I have two set of points in the plane or space, which could be for instance radar contacts over two successive scans. I'd like to pair them so that the sum of squared distances is minimal.
One difficult case, if for instance there is a serie of aligned and equidistant points in the first set, can be found in the second one shifted by one interval (they all moved together). The sum of squared distances does promote the desired solution, but if for every point we look for the closest match in the second set, we go in the wrong way.
I somewhat suspect that the problem can't be solved for the absolute minimum without checking all possible sets of pairs. But maybe there is a heuristic for finding a local minimum that would be the absolute one in most cases?