1.
If you ~ on one particular aspect of something, you give all your attention to it.
The critics immediately homed in on the group’s newly-elected members.
PHRASAL VERB: V P on n
2.
If something such as a missile homes in on something else, it is aimed at that thing and moves towards it.
Two rockets homed in on it from behind without a sound...
PHRASAL VERB: V P on n
see also homing