Abstract: A covert aircraft detection system for a submarine is described which inces an acoustic antenna array and a signal processor to process the acoustic signals to provide the location of the detected aircraft and to classify the detected aircraft. The acoustic antenna array is mounted on the submarine mast and includes a vertically extending rod having a microphone and connected thereto three or more folding legs having microphones connected thereto. The microphones detect the aircraft acoustic signals and these signals are transferred to the signal processor which provides the location of the aircraft and matches the acoustic signal with the database of aircraft acoustic signals to classify the type of aircraft. When the acoustic antenna array is connected to a rotatable mast, such as a periscope, a rotary encoder and mast bearing indicator are utilized to account for the rotation of the acoustic antenna array and the rotation of the mast, respectively.

Abstract: Submarines are provided with underwater self-propelled vehicles that are nched from the submarines and guided by trailing fiber optic cables. Each underwater vehicle has a hull that is separable, and that defines a socket for mating with one end of the separable forward hull portion of another identical vehicle. The separable hull portions of one vehicle, when separated remain connected by a fiber optic line so that a homing device on this line can be used to link up with the transponder aboard the other vehicle. Wings on the latter vehicle guide the line toward a socket that accepts or mates with the end of the one vehicle hull portion.

Abstract: A spring force loaded contact wheel mounted in a stationary position relae to a reciprocating shaft is disclosed. The apparatus of the present invention includes a tensioning assembly for maintaining absolute contact between the contact wheel and the reciprocating shaft wherein the tensioning assembly urges the contact wheel against the shaft to maintain contact therebetween so that the wheel turns as the shaft is linearly displaced. A rotary encoding device is coupled to the wheel for translating the angular and rotational movement thereof into an electronic signal for providing linear displacement information and derivative data with respect to displacement of the shaft.