Abstract: An apparatus for stabilizing the spin axis of a rotating system, the rotating system having a rotor and motor means to cause rotation of the rotor about the spin axis and a magnet, windings, a source of drive current and an actuator combined with the motor means and forming a source of actuator current energizing the windings to generate a radial force which stabilizes the position of the spin axis and dampens other than rotational movements of the rotor.

Abstract: A bearing assembly having a shaft member having a bearing race and a piezoelectric member opposing the bearing race is situated so that when a voltage is applied to it, it expands against the bearing race so that a preload of the bearing is varied. The assembly includes a rotor having two outer bearing races opposing the shaft's inner bearing races. The contact angle for the upper bearing races is different than for the lower bearing races. In one embodiment of the present system, the piezoelectric member is disposed between the shaft member and the bearing race for varying the radial position of the bearing race. In another embodiment, the piezoelectric member is disposed for varying the axial position of the bearing race. In one embodiment, the system includes a hydrodynamic bearing assembly having a stator member having a hydrodynamic surface and a rotor member having a surface facing the stator member hydrodynamic surface.

Abstract: An apparatus for stabilizing the spin axis of a rotating system, the rotating system having a rotor and motor means to cause rotation of the rotor about the spin axis and a magnet, windings, a source of drive current and an actuator combined with the motor means and forming a source of actuator current energizing the windings to generate a radial force which stabilizes the position of the spin axis and dampens other than rotational movements of the rotor.

Abstract: An apparatus for stabilizing the spin axis of a rotating system, the rotating system having a rotor and motor means to cause rotation of the rotor about the spin axis and a magnet, windings, a source of drive current and an actuator combined with the motor means and forming a source of actuator current energizing the windings to generate a radial force which stabilizes the position of the spin axis and dampens other than rotational movements of the rotor.

Abstract: A method of damping resonances in a rotating system is disclosed, which includes developing a representation of vibrating movement in the rotating system, taking the derivative of that representation and applying an out-of-phase active damping force based on the derivative to the rotating system to damp out the movement.

Abstract: The invention relates to the processing of the multiple paths in an interrogator station which, in response to a salvo of interrogations, receives responses in the form of pulses. The station comprises at least two reception channels. The responses to each interrogation of one and the same salvo are classified by order of appearance. A value of dispersion of the energies is estimated, for each channel and each salvo, on the responses having the same classification. Since the first classified response is, by assumption, considered to have arrived by a direct path, the following responses will be eliminated, on the grounds that they have been received after passing through multiple paths, if their values of dispersion of energy on the two paths are not equivalent to those of the first response.