In 2551, an important spin-off of the P-Comm device was developed. Scientists discovered that by coupling a working P-Comm transceiver system with a doppler radar set, they could obtain a visual or aural picture of the surrounding sphere of T-space. This joining of the two systems became known as the T-doppler, and allowed operators to see approaching and departing ships as they traveled in T-space.
Though the T-doppler was a boon to civilian space traffic control, the major benefit was to the military. Because the technology detects approaching ships within only a certain sphere, it must be used with a well-planned warship picket strategy in order to prepare a proper defense.