Pearl Harbor thought.

[CCIP]

Originally Posted by Wolferz

There was no radar in '41 so no IJN plane could have been spotted except with the MKII eyeball.

That's not true. Opana was opened in 1939, using a 1937-model radar. I would seriously doubt the performance of that radar in any sort of precision, but it did detect the Japanese coming in to bomb Pearl, about 40 minutes before the bombing commenced. They thought it was just a flight of B-17s doing training, then they lost contact, and the warning wasn't passed on. So much for precision.