Michigan Aerospace Corporation

University of Michigan

Michigan Aerospace Cororation

Hays, Fisk, Moors, LLC

Paul Byron Hays

Peter Tchoryk

David Michael Zuk

Greg Alan Ritter

David Keith Johnson

Charles J Richey

Jane Pavlich

Anthony Beckman Hays

Scott K Lindemann

Gregory Joseph Wassick

Michael Thomas Dehring

Scott Kevin Lindemann

The invention is directed to a device and method for conducting measurement of a Doppler shift caused by molecular and aerosol movement while simultaneously providing measurement of temperature using LIDAR. The device incorporates a light source; and a Fabry-Perot etalon having a resonant cavity formed with two plane parallel reflecting surfaces, wherein the light source is positioned relative to the a Fabry-Perot etalon such that light is injected into a plane parallel resonant cavity of the Fabry-Perot etalon at an angle of incidence other than normal to the reflecting surfaces. The Fabry-Perot etalon may be formed with each of the parallel reflecting surfaces having different reflectivities. The light source may be positioned to direct the light to bypass a first reflective surface of the plane parallel resonator cavity, and/or implemented using a divergent light source. In addition, the Fabry-Perot etalon may be formed to include an aperture in at least one mirror surface or an edge portion in at least one mirror surface through which the light is directed into the resonant cavity. The device may also incorporate a detector for detecting a fringe pattern outputted by the Fabry-Perot etalon.

System and method for an edge injection etalon

An apparatus providing for simultaneous measurement of the wind upstream and downstream of a wind turbine uses either a single LIDAR beam split into two beams, each focused upstream or downstream of the windmill, or a multiple beam LIDAR with a first beam source aimed toward the upstream direction of the wind and a second beam source aimed at the downstream direction after the wind has passed through the wind turbine. The apparatus may also use LIDAR to measure wind direction and speed by making measurements along slightly different lines of sight, or by pointing the LIDAR in different directions. Two lines of sight allow measuring wind direction in the plane defined by the two lines of sight. Three non-coplanar lines of sight provide the information necessary to determine a full 3-dimensional wind velocity vector. Further, LIDAR may also be used to measure wind speed by estimating the wind velocity using inputs from both aerosol and molecular components.

Atmospheric measurement system

A magnitude and direction, or a measure responsive thereto, of a velocity (V) of a first portion () of an atmosphere () are determined from at least first and second portions of scattered light () generated along a common beam of light () within the first portion () of the atmosphere () and received along linearly independent directions at locations that are relatively remote with respect to one another, at least one of which is relatively remote from a source () of the beam of light ().

A portion of a first portion of light (') from a source of light () is masked by a mask (), and the resulting masked first portion of light (&#x2033;) is combined using a beam splitter optic () with at least one second portion of the light () that had been subject to scattering by a medium (&#x2033;). The mask () is configured so that interference patterns () generated from the first and at least one second portions of light are substantially mutually exclusive even though those interference patterns () would otherwise overlap one another absent the mask ().

Light processing system and method

A fringe pattern from an interferometer is imaged onto a digital micromirror device containing an array of micromirrors in an associated pattern of pixel mirror rotational states that provide for sampling the circular fringe pattern in cooperation with one or more associated photodetectors, so as to provide for generate a corresponding set of associated complementary signals. A plurality of different sets of associated complementary signals generated for a corresponding plurality of mutually independent associated patterns of pixel mirror rotational states are used to determine at least one metric associated with the circular fringe pattern.

Light scattered by a portion of a fluid medium illuminated by a beam of substantially monochromatic light is received within a field-of-view nominally along an axis oriented in a different direction relative to the beam and processed by an interferometer to generate a corresponding fringe pattern that is detected and processed to generate at least one measure of the fluid medium at a plurality of different ranges.

Range imaging lidar

At least one second beam of light from a first beam of light generated by a laser is directed into an atmosphere. Light therefrom scattered by molecules or aerosols in the atmosphere is collected by at least one telescope as at least one light signal, which together with a reference beam from the first beam of light are simultaneously processed by a Fabry-P&#xe9;rot etalon, and resulting fringe patterns are imaged onto a detector adapted to output a resulting at least one signal responsive thereto.

Optical air data system

At least one second beam of light from a first beam of light generated by a laser is directed into an atmosphere. Light therefrom scattered by molecules or aerosols in the atmosphere is collected by at least one telescope as at least one light signal, which together with a reference beam from the first beam of light are simultaneously processed by an interferometer, and resulting fringe patterns are imaged onto a detector adapted to output a resulting at least one signal responsive thereto. In various aspects: a data processor gates the signal to provide a range-responsive measurement; the light signal is multiplexed; a circle-to-line interferometer optic transforms an at least partially circular fringe pattern to a substantially linear fringe pattern; or a CCD detector provides for recording a range-resolved image by successively transferring charges from one adjacent row of photosites to another.

At least one second beam of light from a first beam of light generated by a laser is directed into an atmosphere. Light therefrom scattered by molecules or aerosols in the atmosphere is collected by at least one telescope as at least one light signal, which together with a reference beam from the first beam of light are simultaneously processed by an interferometer, and resulting fringe patterns are imaged onto a detector adapted to output a resulting at least one signal responsive thereto. A data processor determines at least one air data product responsive thereto.

At least one second beam of light from a first beam of light generated by a laser is directed into an atmosphere. Light therefrom scattered by molecules or aerosols in the atmosphere is collected by at least one telescope as at least one light signal, which together with a reference beam from the first beam of light are simultaneously processed by an interferometer, and resulting fringe patterns are imaged onto a detector adapted to output a resulting at least one signal responsive thereto. In various aspects: a plurality of transversely separated light collectors collected the scattered light; at least two telescopes are associated with a common second beam of light; or the telescope is coupled to a gimble mount that provides for positioning a region of overlap of the second beam of light with the field of view of the telescope.

A first beam of light from a laser is split by a beam splitter into a reference beam and at least one second beam of light, the latter of which is directed into an atmosphere. Light from the at least one second beam of light scattered by molecules or aerosols in the atmosphere is collected by at least one telescope as at least one light signal. The at least one light signal and the reference beam are simultaneously processed by a common interferometer, and resulting fringe patterns are imaged onto a detector and processed by a data processor to determine at least one associated air data product.

A first beam of light from a laser is split by a beam splitter into a reference beam and at least one second beam of light, the latter of which is directed from an optical head into an atmosphere. Light from the at least one second beam of light scattered by molecules or aerosols in the atmosphere is collected by a corresponding at least one telescope of the optical head as at least one light signal. The at least one light signal and the reference beam are simultaneously processed by different portions of a Fabry-P&#xe9;rot interferometer, and resulting fringe patterns are imaged onto a detector and processed by a data processor to determine at least one associated air data product.

Molecular optical air data systems (MOADS)

An improved, temperature-compensated piezoelectric force motor features greater dynamic range and robustness as compared to previous motor designs. By implementing positive and negative expanding elements, the overall motor length is held constant over temperature. A central stretching member removes the PZT element from the load path of the motor when the motor is relaxed, thereby preventing damage to the element during assembly and deployment. When the piezoelectric element is powered, the central structural member also improves the failure strength of the assembly to further increase the robustness of the motor design. The invention finds applicability in various commercial products including, but not limited to, scientific etalons, nanopositioning systems, custom fiber optic assemblies, and custom CCD detectors.

Temperature-compensated piezoelectric force motor

Methods and apparatus are employed to enhance the efficiency and applicability of Fabry-Perot interferometers. In existing devices, light introduced at a first off-axis point on the image plane is partially transmitted through the interferometer to the detector and partially reflected to a second off-axis point on the image plane. Broadly, the invention re-uses the light reflected to the second off-axis point rather than discarding it. As one example, the reflected light is guided to a third off-axis point on the image plane for retransmission back through the interferometer to a different point on the detector. A plurality of optical fibers are employed, each having one end to receive light at an off-axis point of the image plane, and another end to re-direct the light back through the etalon from a different off-axis point of the image plane. Alternatively, the reflected light is guided to a second detector, which may, in fact, form a portion of a second interferometer. As a further alternative, a mirror or other reflective element may be used to redirect the light back to the same point on the detector. In each case, the angular coherence of the light is preferably randomized prior to the subsequent detection. A multi-mode optical fiber is preferably used to carry the redirected light, which conveniently acts to randomize the angular coherence of the light during its travel.

Off-axis coupled etalon interferometers

An optical system employs an internally conical reflector for converting circular fringe information, such as that which is produced by a Fabry-Perot Interferometer, into linear information whereby the reflected light can be received by conventional linear array detectors, such as charge coupled device which are used in spectroscopic analysis. The azimuthal angle of the detected circular fringe pattern is reduced with the use of a tele-kaleidoscope having a predetermined arrangement of mirrors. Electromagnetic energy which is issued from the interferometer is propagated substantially along the conical axis of the cone of which the reflector forms a segment, and is reflected and focused substantially onto a line in the vicinity of the conical axis, where the linear detector is situated. In a preferred embodiment, the apex of the cone is situated where the conical axis intersects the focal plane of the circular fringe pattern.

Growing community of inventors

Ann Arbor, MI, United States of America

Paul Byron Hays