TLS NexGen uses interferometric techniques to determine the location of a signal that is being carried over a satellite transponder. This method is totally passive and requires only that the TLS site be in the transponder "footprint" of both the interfered satellite and an adjacent satellite that has a transponder closely matching the characteristics of the interfered transponder.

The TLS NexGen system determines the transmitter's location by observing the difference in arrival times and frequencies caused by transmission of the interfering signal through two satellites. Using this technique and accurate satellite orbital information, it is typically able to report position accuracy to within a few kilometers. In most cases, this accuracy is more than sufficient to allow identification of the transmitter and elimination of the interfering signal.

The very small location ellipse displayed on the left was generated from an actual TLS activation, and is typical of the results obtainable with the TLS NexGen. The center of position ellipse shown, located near Bloomington, Illinois, was only 3 km from the actual location of the signal source.

Using the results obtained with the TLS NexGen, the satellite operator can concentrate his efforts into a small geographic region, isolate the source of the interference, and shut it down. Without TLS, the interference can often last for days, weeks, or longer.