Its commonly known that time since detection isn't a useful statistic for a radar, it could be used to continue tracking an object however it doesn't really function as it appears to be intended. A bigger issue is that an enormous ship shows on the radar the same as a player or npc walking on the deck of it, there is simply no solution to this right now. In real life the radar to some degree can detect the size of the objects, I think this should replace 'time since detection' or perhaps a checkbox on the radar options you can select.

This would allow for systems to target specific things, filter out players and even a potential iff system.