The other thought I had is in response to the question, why the enemy would want to jam it at all, since it would be useful to them too. Why not introduce a widely variable (10s of km) error, but have the error factor known to own forces? Nice bit of disinformation warfare. Much more sophisticated than jamming
Nice idea, but unless the error changed randomly, all you would have to do to counter is go to a known location and measure the difference.
