Definition
The time required for a radar pulse to travel one nautical mile out to a target and return to the antenna — approximately 12.36 microseconds.
Plain English
The tiny amount of time it takes for a radar signal to fly out one nautical mile, bounce off something, and come back. Radar uses this round-trip time to figure out how far away a target is.
Context Anchor
Seen in radar and distance-measuring discussions, especially when explaining how electronic equipment turns signal timing into distance.
Derivation
‘Radar’ comes from RAdio Detection And Ranging. The ‘mile’ here is a nautical mile — the standard unit for aviation distance. So a ‘radar mile’ is the time radar needs to measure one nautical mile of range.
Why Pilots Care
Correct use ensures accurate interpretation of radar distances and prevents range errors in navigation.
Analogy
Like shouting in a canyon and timing the echo. The longer the echo takes to return, the farther away the wall is. Radar does the same thing, just much faster and with radio waves.
Grounding Statement
If the return takes longer to come back, the target is farther away.
Intuition Check
A radar mile is not a different kind of physical mile on the ground. It is the time delay that represents one mile of radar-measured distance.
Example Sentence 1
Because each radar mile is about 12.36 microseconds, a target at 50 nautical miles takes roughly 618 microseconds to produce a return.
Example Sentence 2
Timing the return pulse in radar miles helped confirm the exact distance to the waypoint.