Michigan Aerospace Corporation

Environmental Research Institute of Michigan

Honeywell International Inc.

Michigan Aerospace Cororation

Hayes, Paul, Byron

Tchoryk, Peter

David Michael Zuk

David Keith Johnson

Paul Byron Hays

Peter Tchoryk

Charles J Richey

Dominique Claire Fourguette

Vernon L Larrowe

Scott K Lindemann

Parviz Tayebati

Jane Pavlich

Xiao Zhu Fan

Grant Lodden

Matthew Wiebold

Robert J Maxwell

Marvin J Holter

Scott Kevin Lindemann

Charles Richey

A number of etalons together are used to extract the velocity, density and temperature of a scattering medium, such as the atmosphere. An optical air data sensor system incorporates the structure and operation for outputting laser light at a volume of air so as to be scattered by molecules and aerosols in the air volume being scanned; receiving the scattered laser light via a collecting optics assembly; splitting the received scattered laser light from the input optical fiber into a plurality of scattered light emissions; collimating each of the plurality of scattered light emissions; inputting the plurality of collimated light emissions into corresponding ones of a plurality of Fabry-Perot etalons; and imaging each of the plurality of collimated light emissions from the plurality of Fabry-Perot onto corresponding ones of a plurality of non-imaging detectors.

Multi-element Fabry-Perot etalon interferometer for direct detection lidar

A system for obtaining air data for a vehicle comprises a laser device that emits laser light pulses, and transmit optics that transmits the light pulses into an external air volume adjacent to the vehicle. The system also includes receive optics that collects scattered portions of the light pulses from the external air volume, and a whispering gallery mode (WGM) frequency discriminator that receives the scattered portions of the light pulses from the receive optics. The WGM frequency discriminator includes at least one WGM resonator that outputs a selected portion of the light pulses at one or more optical signal frequencies via tuning the WGM resonator other than by an electro-optic effect. An optical detector samples the selected portion of the light pulses from the WGM frequency discriminator, and converts the sampled light pulses to scalar values. A processing unit receives and records the scalar values from the optical detector.

Whispering gallery mode based range-resolved air data system

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 system for scanning light to define a range gated signal includes a pulsed coherent light source that directs light into the atmosphere, a light gathering instrument that receives the light modified by atmospheric backscatter and transfers the light onto an image plane, a scanner that scans collimated light from the image plane to form a range gated signal from the light modified by atmospheric backscatter, a control circuit that coordinates timing of a scan rate of the scanner and a pulse rate of the pulsed coherent light source so that the range gated signal is formed according to a desired range gate, an optical device onto which an image of the range gated signal is scanned, and an interferometer to which the image of the range gated signal is directed by the optical device. The interferometer is configured to modify the image according to a desired analysis.

System and method for scan range gating

One of first and second beams () of corresponding first and second light () are projected into an atmosphere () and at least one physical property of the atmosphere () is detected from the interference pattern () generated from the resulting scattered light (). The first and second beams () are selected responsive to either a detected signal-to-noise ratio (SNR) or a detected aerosol-to-molecular ratio (AMR). The wavelength () of the first light () provides for either molecular or aerosol scattering, whereas the wavelength () of the second light () provides for primarily only aerosol scattering. In accordance with a second aspect, scattered light () from one or more beams () of substantially monochromatic light () projected into the atmosphere () and received from a plurality of interaction regions () or measurement volumes () provides for determining wind power (P*) within a region of the atmosphere ().

Atmospheric measurement system and method

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

A range dispersion sensor operative to detect objects of a preselected height 'h' operates on quarterwave interference principles. Electromagnetic energy is modulated at a first frequency f.sub.1 such that objects of the preselected height h disposed upon a background create a quarter-wave length reflector. A beam of electromagnetic energy reflected from an object of height h and its proximate background interferes destructively to create a null signal. Effects of non-uniform reflectivity are normalized by modulating the beam at a second frequency f.sub.2 selected to not create constructive or destructive interference effects with objects of the preselected height. The ratio of the two signals is taken thereby normalizing the effects of non-uniform reflectivity, and the resultant ratio is indicative of the height of the objects.

Range dispersion sensor

A pattern recognition system for use with a two-dimensional image, each point associated with a height and with contributions from various wavelengths of light. The image to be analyzed is first sensed by a sensor and stored in a memory. Signals, read from the memory, are filtered and processed to produce signals measuring each of the wavelengths and measuring the height. The resulting distributions of data are first scanned for areas containing appropriate height measurements. Each pixel of these areas is classified according to predetermined classification definitions, further reducing the areas to be processed. These areas are subjected to spatial classification according to other classification definitions. The spatial classification may be accomplished by a neighborhood processor. The areas of the image are then identified with the features to be recognized.

Multispectral/spatial pattern recognition system

An apparatus for measuring the phase difference between two signals including a precision extender employing a frequency multiplier for each of the signals, apparatus for heterodyning each of the signals back to their original frequencies, and a phase detector for measuring the phase difference of the heterodyned signals.

Apparatus for extended precision phase measurement

An image sensor for generating multi-bit digital pixel values for analyses in a digital image processor. A phase detector is utilized for detecting the relative phase difference between a modulation reference waveform for modulating a light source and the reflected information waveform from the illuminated target area. A high speed digital counter is driven by a phase locked loop frequency multiplier. The counter is enabled and reset by digital logic levels derived from the reference and signal waveforms. A latch is provided to store the count on the counter output when the counter is reset to thereby provide a multi-bit digital pixel value representative of characteristics of the target being sensed.

Growing community of inventors

Ann Arbor, MI, United States of America

David Michael Zuk