Minimap - Needs a serious overhaul & bug fix

[Fishy]

Does anyone know how the feature of showing red dots on the mini map is supposed to work? When I say 'feature' I mean under what circumstances should one expect to see a red dot on the current implementation of the mini map? And what does it mean?
Is it tied to empire-owned facilities or the reveal tool of the infiltrator etc? how long does it maintain the 'history' of enemies?
This feature is very unclear to me.
Thank you