An exographic sensor was an application of sensor technology, a security and surveillance tool developed and used by the United Federation of Planets. It had a modified visual transceiver with an assembly that generated and emitted a neutrino wave-guide-modulated carrier signal that traveled from the device and returned after being reflected and altered by distant objects of interest, allowing its user to "see" them—even through solid matter. The incoming modulated data was converted into a humanoid-interpretable video display matrix by first reassembling the reflected neutrino-based wave-guide-carrier signal into a video signal, then shifting the received data's bandwidth to within the visible frequency spectrum. Altering the emitted wave frequency to the proper setting allowed the sensor to capture and display data about certain objects that would otherwise be undetectable without such user-adjustments.
Limitations to the device included the inability to transmit and receive signals through objects and media of a sufficiently high density ("ultra-dense" materials). Also, any subspace interference prevented the exographic sensor from functioning or returning useful data to the user. (Decipher RPG module: Starfleet Operations Manual)