Dodgeball -- Can a Satellite Avoid Being Hit by Debris?

Can a satellite dodge a collision with untracked orbiting debris? Can a satellite dodge collision with a tracked object, making only the avoidance man{\oe}uvers actually required to avoid collision, despite the uncertainties of predicted conjunctions? Satellite-borne radar may distinguish actual collision threats from the much greater number of near misses because an object on a collision course has constant bearing, which may be determined by interferometric detection of the radar return. A large constellation of such radars may enable the determination of the ephemerides of all cm-sized debris in LEO.