Blink

The interceptors came up with descriptions of the fists and
styles of the operators they were following. They assigned them
names and assembled elaborate profiles of their personalities.
After they identified the person who was sending the message,
the interceptors would then locate their signal. So now they
knew something more. They knew who was where. West goes
on: “The interceptors had such a good handle on the
transmitting characteristics of the German radio operators that
they could literally follow them around Europe — wherever
they were. That was extraordinarily valuable in constructing an
order of battle, which is a diagram of what the individual
military units in the field are doing and what their location is. If
a particular radio operator was with a particular unit and
transmitting from Florence, and then three weeks later you
recognized that same operator, only this time he was in Linz,
then you could assume that that particular unit had moved from
northern Italy to the eastern front. Or you would know that a
particular operator was with a tank repair unit and he always
came up on the air every day at twelve o’clock. But now, after
a big battle, he’s coming up at twelve, four in the afternoon,
and seven in the evening, so you can assume that unit has a lot
of work going on. And in a moment of crisis, when someone