Considering the issues with shipborne data acquisition & processing vs. satellite & terrestrial acquisition with ground based processing, I have to wonder why the second wouldn't be the method of choice. Avoidance information can be easily transmitted to ATC & aircraft.
Jeez, some of theaircraft I fly have satellite weather downlinks showing compilation terrestrial radar, TAFs, METARS and the like, and traffic uplinks. Damned if I can see why similar wouldn't be possible in near enough real time for ash avoidance