Abstract: A method and apparatus for sensing both axial and angular displacements of a collar relative to a shaft. The invention provides transmitting and receiving electrodes on the shaft and coupling electrodes on the collar. Displacements in the axial or angular directions vary the amount of signal conveyed between the electrodes relative to the quantities sought to be measured. An electronic package provides the appropriate signals and allows multiplexing of the data.

Abstract: A method and apparatus for measuring the velocity of an object relative to a reference wherein the object has receivers thereon which scan a spatial function which originates from the reference. A signal is developed in each receiver, the value of which is dependent upon the position of the scanning range of the receiver relative to the reference. Signal values from a number of scanning ranges at various positions relative to the object are stored either simultaneously or cyclically at a first instant and then are compared with corresponding signal values obtained at a later time. The displacement of the spatial function relative to the object between the two scanning instants is determined and the velocity of the object is calculated from the magnitude of the displacement and the time elapsing between the scanning instants.

Abstract: Apparatus for measuring a vessel's velocity relative to a reference location includes a transmitter on board the vessel for transmitting a coherent signal toward a reference location from where the coherent signal is reflected, and a receiver on board the vessel which includes at least four spaced-apart receiver transducers. The coherent signal transmitted by the transmitter is within a lobe range that is substantially common to the receiver transducers, the signals reflected by the reference location comprising at least two acoustic signals that are similar in character but different in timing from each other, the difference in timing being a function of the distance in the direction of measurement between the spaced-apart receiver transducers and further being a function of the vessel's velocity, the received signals comprising reflections from every point on the reference location within the lobe range.