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 could not indicate the origin or destination of a ship, but could record its entry or departure, as well as its mass and speed.
- The Star Wars Sourcebook, p. 10 (both editions) (As "Hyperwave Signal Interceptor")
- Imperial Sourcebook, First Edition, p. 101.
- Imperial Sourcebook, Second Edition, p. 103-104.
- Suns of Fortune