A method is provided for adjusting a laser doppler anemometer (1-5) having an emitting optic (3) which emits at least two laser beams (7, 8), and a receiving optic (4) for gathering light scattered by dispersed particles. The method comprises the steps of coupling a laser light (17) into an output of the receiving optic to make a focal point (12) of the receiving optic visible on a spaced reference surface (13); adjusting the receiving optic with respect to the surface so that the focal point of the receiving optic lies on the surface; and adjusting and regulating the emitting optic and the receiving optic with respect to each other so that a crossing point (11) of the laser beams coincides with the focal point of the receiving optic on the surface.
The present invention provides a system and method for collecting data from a Laser Doppler Anemometer of the type including a probe mounted to a controllable traversing system. Velocity and position data is collected from the probe while it is continuously in motion, and displayed in real time. If at any point the data is of unacceptable quality, the data collection process is stopped, the probe is moved to a last known good position, and the data collection process is restarted.
Doppler sensor apparatus has means outputting coherent electromagnetic radiation (2), means (4) for transmitting radiation from the source means (2) to a point in space, means (6) for receiving radiation reflected from the point in space and means (8) for determining any Doppler shift in the reflected radiation. The transmitting means (2) and the receiving means (4) are separate, and the transmitting means (2) and the receiving means (4) are each adapted to have radiation guiding means (26, 28) releasably attached thereto, thereby enabling radiation guiding means (26, 28) for routing radiation from the source means (2) to the transmitting means (4) and from the receiving means to the determining means (8) to be interchanged with radiation guiding means (34, 36) for routing radiation for use in aligning the transmitting means (4) and the receiving means (6) to the transmitting means (4) and to the receiving means (6).
A data input device for use with a tracking surface having light-scattering properties with respect to the device. The device comprising a single laser having a modulated light beam. A beam splitter splits the modulated light beam into two light beams projected along separate paths toward the tracking surface. A portion of the light striking the tracking surface reflects back into a cavity of the single laser for self-mixing with the projected light, thereby altering first and second characteristics of the projected modulated light beam according to first and second directions associated with the tracking surface. A detector associated with the laser detects the altered first and second characteristics of the modulated light beam projected by the laser, and a controller responsive to the detector determines the relative movement of the tracking surface and data input device relative to one another as a function of the altered first and second characteristics detected by the detector.
