A plain-English reference for the technical terms used in professional bug sweeping, surveillance detection, vehicle tracker investigations and meeting-room privacy assessments.
TSCM can quickly become technical. This glossary explains common terms without assuming an electronics background. It is intended to help clients understand what a provider means when discussing methods, findings and limitations.
Technical Surveillance Counter-Measures. A structured process for identifying and evaluating technical surveillance risks using appropriate electronic and physical inspection methods.
Radio frequency. Electromagnetic energy used by radio, mobile, Wi-Fi, Bluetooth and many other wireless systems.
An instrument that displays signal amplitude or power against frequency, allowing an engineer to examine carriers, bandwidth, bursts and other RF activity.
A simple instrument that responds to RF energy over a broad frequency range. Useful as an indicator, but often unable to identify the source.
Non-linear junction detector. A specialist instrument used to locate semiconductor electronics by observing harmonic responses, including electronics that may be switched off.
A radio technique that changes carrier frequency according to a sequence. Brief hops can make simplistic detection and interpretation more difficult.
A transmitter that sends information in short periods rather than continuously, reducing the time during which it is visible on air.
A device records information locally and transmits it later. It can therefore be radio-silent while recording.
A legitimate signal, object or material produces an indication that is incorrectly interpreted as a surveillance threat.
A threat is present but the chosen method produces no useful indication, potentially creating false reassurance.
The process of narrowing down the physical source of a signal or anomaly rather than merely observing that it exists.
A tracking device may use satellite navigation to determine position and cellular, radio or other communications to report it. Not every tracker is continuously transmitting or magnetically mounted.
Legitimate built-in vehicle systems that may contain GNSS, cellular and other radios. These can complicate tracker investigations because normal vehicle electronics must be separated from unexplained additions.
How effectively a room prevents speech from being understood outside the intended private area. It is separate from whether a hidden bug is present.
The reduction in RF signal level between one location and another, for example from inside a meeting room to outside its boundary.
A reasoned evaluation of what forms of surveillance are plausible given the environment, access, information at risk and circumstances.