A targeting sensor was a component of Federation and Klingon weapons, as well as Starfleet sensors.
In 2154, the shuttlepod piloted by Travis Mayweather lost their targeting sensors because of several hits by two Vulcan fighters. Reed noticed that the plasma cannons are still online. (ENT: "Awakening")
In 2371, Benjamin Sisko ordered Miles O'Brien to overhaul the USS Defiant's targeting sensors in preparation for a possible encounter with the Tzenkethi. (DS9: "The Adversary")
In 2374, Lamat'Ukan realigned the targeting sensors of the Defiant, removing errors in the tracking subroutines. (DS9: "One Little Ship")
In 2375, the disruptor targeting sensors of the IKS Ch'Tang needed to be replaced. (DS9: "Once More Unto the Breach")