Newps writes:

Can you picture the radar screen in Boston/New York/Chicago/LAX
when all the planes on the ground are showing up? The radar sweeps
by and shows 23 planes lines up for the departure runway,
superimposed on whoever is flying overhead.

Irrelavant. The radar computer has software that will not show any
target within the user specified distance from the radar antenna.
[...]

Maybe, but it is still a problem for aircraft with TCAS, who
receive false alarms due to the ground traffic.

- FChE