Abstract: Predictively adjusting the pitch of blades and/or sections of a blade based on fluid velocity measurements. In one embodiment, the measurements are obtained of an upstream portion of a fluid flow using a laser Doppler velocimeter. The pitch of the blade(s) and/or blade section(s) are then adjusted to achieve a desired amount of lift or to create a stall-configuration as can be useful for conditions in which an excessive fluid velocity is detected.

Abstract: Predictively adjusting the pitch of blades and/or sections of a blade based on fluid velocity measurements. In one embodiment, the measurements are obtained of an upstream portion of a fluid flow using a laser Doppler velocimeter. The pitch of the blade(s) and/or blade section(s) are then adjusted to achieve a desired amount of lift or to create a stall-configuration as can be useful for conditions in which an excessive fluid velocity is detected.

Abstract: Predictively adjusting the pitch of blades and/or sections of a blade based on fluid velocity measurements. In one embodiment, the measurements are obtained of an upstream portion of a fluid flow using a laser Doppler velocimeter. The pitch of the blade(s) and/or blade section(s) are then adjusted to achieve a desired amount of lift or to create a stall-configuration as can be useful for conditions in which an excessive fluid velocity is detected.

Abstract: Predictively adjusting the pitch of blades and/or sections of a blade based on fluid velocity measurements. In one embodiment, the measurements are obtained of an upstream portion of a fluid flow using a laser Doppler velocimeter. The pitch of the blade(s) and/or blade section(s) are then adjusted to achieve a desired amount of lift or to create a stall-configuration as can be useful for conditions in which an excessive fluid velocity is detected.

Abstract: A method and apparatus for laser Doppler velocity measurements with a fixed difference, dual beam receiver and using a non-laser, stable frequency reference.

Abstract: A magnetic process and apparatus for separating out small electrically conductive particles dispersed in a finely ground, relatively non-conductive medium by means of magnetic fields. More specifically, a steady or relatively slowly varying field is provided, and a higher frequency magnetic field induces magnetic dipoles into the conducting particles, which are displaced by the steady magnetic field to thereby effect separation. The magnetic separation process selectively applies a force on a conductive particle so as to either remove it from the bulk of the non-conductive material or increase the concentration of conductive particles in a given volume of space. The effectiveness of the separation process improves with increasing size of the particle; however, the process can be used for particle sizes that would be classed as "very fine".

Abstract: An aircraft is provided with wind velocity measuring equipment which measures the wind velocity both (1) close to the aircraft and (2) at a considerable distance such as one-half mile or a mile away from the aircraft; and a large difference in these two measured velocities indicates dangerous windshear conditions. Either a warning signal is given to the pilot, or automatic control apparatus is actuated, to avoid crash conditions. A single pulsed carbon dioxide (CO.sub.2) laser velocimeter may be mounted in the aircraft for measuring both the close-in and the distant wind speeds. The laser optic focus is shifted between the near and far measurements, and the return signal is time gated to increase signal-to-noise ratio.