Here is what I am planning to do with radar. This is the plan, not a finished feature, so details may change as we test it.
The map will show enemy contacts 2 different ways.
Radar contacts
A plane within range of your side's radar and above radar height shows on the map as it does today. Position updates will be faster, something like every 5 seconds. Between updates the contact fades to about 25%, so you can tell how old the position is.
Seen contacts
Being near an enemy will no longer put him on your side's map. Someone on your side has to actually see him. You have seen him if he is within vis range and really in your view, so he does not count if he is off screen, behind your canopy frame, behind terrain or in the sun, or if either of you is inside a cloud. As soon as anyone on your side sees him he shows on your side's map. He stays while anyone keeps seeing him and for a little while after. Seen contacts have their own update rate, 20 seconds by default.
What this means in play
Flying under radar no longer shows you just because an enemy is nearby. If nobody spots you, you stay off their map. Flying inside a cloud, the sun and blind spots now hide you from the whole enemy side, not just the one pilot. Keeping your eyes on a contact helps your team.
Plain dots
Each arena can choose, for each type of contact, to show full detail or just a plain dot. Full detail is plane type and heading, as now. A dot tells you something is there but not what it is or where it is going. So an arena could show radar contacts as dots and seen contacts in full detail.
Your own side does not change. Friendly planes still show with full detail.
GVs may also be able to show as seen contacts. That would be an arena setting.
HiTech