Hyperwave signal interceptor

A hyperwave signal interceptor (HSI) was a sensor that detected the telltale fluctuations in the local hyperspace field that resulted whenever a starship entered or exited hyperspace. They cannot indicate the origin or destination of a ship, but can record its entry or departure, as well as its mass and speed.

HSIs can also be used to tap into hyperradio transmissions, like those sent by subspace radio or on the HoloNet.