We have the ability to set a tonne of radar settings...
a) Range and altitude of the radars at the airfields (dots inside the circle)
b) Range and height of sector radar at which you'll appear (bars)
c) Ability to turn on or off the radar for friendly, enemy, planes only, etc.
d) Ability to adjust the range in which bases will flash for all crafts.
e) Range at which enemy identifier will appear above an aircraft. Friendly is always 10 miles.
That being said, HiTech gave us a few tips on radar settings to make it a better arena: full friendly/enemy. That is perhaps a closer setting to true dar capabilities of WWII. We just lack ground control stations to relay that information to us.