Temporal Monitor
From Tardis Wiki, the free Doctor Who reference
Numerous Temporal Monitors were present in the Temporal Control Room, which the Time Lords used to observe the time streams of the universe. (PROSE: The Three Doctors, TV: The Three Doctors)
As a Time Lord messenger told the Third Doctor, the Time Lords had used "the Monitor" to track the Master to Earth before losing contact as a result of "some kind of alien interference". As the Doctor discovered, the Master was working with the Nestene Consciousness. (PROSE: Doctor Who and the Terror of the Autons)
