I would have to show you. This is where the genius shines of how the radar was made to function in the game.
Ask me when 3.6.10 hits. We used to teach this to people who rolled onto PXO and didn't know how to play past the singleplayer/didn't have much experience with multi in general.
I would assume there's others who know how to do this who could show you as well (or explain it in a way that I can't), but surprisingly, back in the PXO days, even where there were droves of people abound, only the specific "hardcore" group knew this down to a science (among other things obviously), while many others (read:everyone else) didn't.