Rosemount Aerospace Limited

Mark Ray

Kaare Josef Anderson

James R Jamieson

Clinton T Meneely

Mark Sherwood Miller

Michael Paul Nesnidal

Darren Glenn Jackson

Kent Allan Ramthun

Gary E Halama

James W Swenson

David Michael Socha

Jennifer M Alexander

Joseph T Pesik

Magdi A Essawy

Malcolm B McIntosh

Clinton T McNeely

An optical sensor for an aircraft includes two detectors, a light source, and a controller. The detectors are oriented along detector paths and have tilt angles and fields of view. The detectors are configured to detect light reflected from an illumination volume and to generate detector signals that correspond to intensities of detected light. The tilt angles are equal such that each detector is oriented in an opposite direction within a plane containing a light source path and the detector paths. The light source is oriented along the light source path and is configured to illuminate the illumination volume which overlaps with the fields of view within a predetermined distance range. The controller is configured to receive the detector signals, detect whether a cloud is present based upon the detector signals, determine a cloud phase, and calculate a density of the detected cloud.

Multiple angled field-of-view cloud sensor

A system for determining parameters of a cloud atmosphere within a wind tunnel. The system includes: a light projector configured to project a pulse of light energy into a projection field of view; at least one light detector having a detection field of view that forms a range-limited intersection with the projection field of view, the range-limited intersection having a maximum sampling range so as to exclude wall structures of the wind tunnel, wherein the at least one light detector is configured to detect a backscattered portion of the projected pulse of light energy backscattered from within the range-limited intersection; and a cloud parameter calculator configured to determine parameters of the cloud atmosphere based on the backscattered portions detected.

Multi-fiber single lens optical ice detector

A method of operating an optical icing conditions sensor includes transmitting a first light beam with a first transmitter and a second light beam with a second transmitter, thereby illuminating two illumination volumes. A first receiver receives the first light beam. A second receiver receives the second light beam. A controller measures the intensity of light received by the first and second receivers. The controller compares the intensities to threshold values and determines if either intensity is greater than the threshold values. The controller determines a cloud is present if either intensity is greater than the threshold values. The controller calculates a ratio of the intensities if a cloud is present. The controller determines, using the ratio, whether the cloud contains liquid water droplets, ice crystals, or a mixture of liquid water droplets and ice crystals.

Detection of aircraft icing conditions and discrimination between liquid droplets and ice crystals

Apparatus and associated methods relate to determining an effective size, quantity, shape, and type of water particles in a cloud atmosphere based on differences in amplitudes of optical signals backscattered at different backscattering angles. Off-axis backscattering&#x2014;backscattering at angles other than 180 degrees&#x2014;is affected by the effective size, quantity, shape, and type of water droplets. Detected amplitudes of optical signals that are backscattered at different angles are used to indicate the effective size, quantity, shape, and type of water particles in the cloud atmosphere. In some embodiments, optical emitters and detectors are configured to measure amplitudes of optical signals backscattered at backscattering angles of both on-axis&#x2014;180 degrees&#x2014;and off-axis varieties.

Characterization of a cloud atmosphere using light backscattered at two angles

Apparatus and associated methods relate to a system for detecting foreign object debris ingested into an aircraft engine. The system detects such foreign object debris by projecting a beam of light over an inlet of the aircraft engine. When foreign object debris is ingested into the aircraft engine, it intercepts the beam of light and scatters a back-scattered portion of the intercepted beam of light. An optical detector is configured to detect the back-scattered portion of the intercepted beam of light. A processor is configured to determine whether foreign object debris is ingested by the aircraft engine based on a comparison of a threshold value with a signal indicative of the back-scattered portion generated by the optical detector.

Optical detection of foreign object debris ingested by aircraft engine

Apparatus and associated methods relate to ranging of objects in a scene based on difference images indicative of only objects in the scene that have ranges within a subrange. The difference images are calculated by taking differences of two images, each of which captures light reflected by objects in the scene that have ranges within range domains that are different from one another. Thus, each of the difference images includes light reflected by only those objects located at ranges that are included in one of the range domains but not the other. These range domains are controlled by the timing of operation of a fast shutter. In some embodiments, the fast shutter includes an electro-optical modulator between two polarizing filters. The electro-optical modulator can rapidly change the polarization of the light transmitted therethrough such that the second polarizing filter either transmits or blocks the light.

Ranging of objects in a scene using difference imaging and fast shutter control

Apparatus and associated methods relate to sampling a large volume of a cloud atmosphere so as to obtain a large signal response from even a sparse distribution of water droplets in the cloud atmosphere. Such a volume can be probed by projecting an uncollimated optical beam into the cloud atmosphere and sampling the signal backscattered from the water droplets located within the probed volume. The uncollimated optical beam can be generated by projecting a diverging pulse of light energy from a polished end of a first optical fiber. A second optical fiber can be used to receive the optical signal backscattered from the cloud atmosphere. The second optical fiber can also have substantially the same field of view as the first optical fiber, so as to receive signals from a volume of the cloud atmosphere that is substantially commensurate with the probed volume.

Multi-fiber optical sensor for icing

An aircraft ice detection system is configured to determine a condition of a cloud and includes a radar transmitter, a radar receiver, optics and a splitter. The radar transmitter is configured to produce quasi-optical radiation. The optics are configured to direct the quasi-optical radiation from the radar transmitter to the cloud and receive reflected quasi-optical radiation from the cloud. The radar receiver is configured to receive the reflected quasi-optical radiation from the optics and the splitter is configured to direct the reflected quasi-optical radiation from the optics to the radar receiver.

Airborne ice detector using quasi-optical radar

An aircraft ice detection system is configured to determine a condition of a cloud and includes a radar system, a lidar system, optics and a dichroic filter. The radar system is configured to project quasi-optical radiation to the cloud and receive reflected quasi-optical radiation from the cloud. The lidar system is configured to project optical radiation to the cloud and receive reflected optical radiation from the cloud. The optics are configured to direct the quasi-optical radiation and the optical radiation to the cloud and receive the reflected quasi-optical radiation and the reflected optical radiation from the cloud. The dichroic filter is configured to direct the quasi-optical radiation from the radar system to the optics, direct the optical radiation from the lidar system to the optics, direct the reflected quasi-optical radiation from the optics to the radar system and direct the reflected optical radiation from the optics to the lidar system.

Apparatus and associated methods relate to reliably determining both size of large water droplets and density of small water droplets in a multi-modal cloud atmosphere. A pulsed beam of light is projected into the cloud atmosphere and a receiver receives a reflected portion of the projected pulsed beam backscattered by the cloud atmosphere. The received reflected portion is split into first and second parts. First and second parts are directed to first and second detectors, each having a different gain. A ratio of the gains of the first and second detector is greater than 3:1, thereby providing a low-gain detector for producing unsaturated signals indicative of scintillation spike reflection by large water particles and a simultaneous high-gain detector for producing signals indicative of range-resolved reflections by numerous small water particles.

System and method for measuring cloud parameters

An aircraft system is configured to detect conditions of a cloud. The aircraft system includes a laser emitter, a fluorescent filter, optics, and an imager. The laser emitter generates a short pulse laser beam. The fluorescent filter is configured to convert the short pulse laser beam into a short pulse light beam such that the spectral content of the short pulse light beam is greater than the spectral content of the short pulse laser beam. The optics are configured to direct the short pulse light beam through a window of the aircraft into the cloud. The imager is configured to receive a reflected portion of the short pulse light beam from the cloud, and process the images to detect the cloud particles of interest.

Microscopic imager for aircraft cloud condition detection

Apparatus and associated methods relate to determining a size and/or density of Super-cooled Large Droplets (SLDs) in a cloud atmosphere by simultaneously projecting both a collimated pulsed beam into a narrow-field projection volume and a divergent pulsed beam into a wide-field projection volume of the cloud atmosphere, and then detecting both the collimated and divergent pulsed beams backscattered from within a detection volume of the cloud atmosphere. Projection and detection are configured such that the detection volume intersects both the narrow-field and the wide-field projection volumes defining narrow-field/detection and wide-field/reception detection volumes, respectively. A distance between the narrow-field/detection intersecting volume and the generating and detecting apparatus is greater than a predetermined distance, thereby avoid detection of light backscattered from within the atmosphere located in a disturbance region of the cloud atmosphere within the predetermined distance from the apparatus.

Apparatus and associated methods relate to a system for interfacing with an optically-powered sensor. The system includes an optical emitter configured to emit a beam of optical energy so as to provide operating power for the optically-powered sensor. The system includes an optical detector configured to detect a time sequence of optical pulses generated by the optically-powered sensor, the time sequence of pulses modulated between first and second optical power levels. The system includes a parameter extractor configured to determine a value of a sensed parameter based on the time sequence of optical pulses detected by the optical detector. The system also includes a power controller configured to control power level of the emitted beam of optical energy based on the first and/or second optical power levels detected by the optical detector.

System for interfacing with an optically-powered sensor

Apparatus and associated methods relate to determining, based on a detected portion of a projected pulse of quasi-optical energy backscattered by water particles within a divergent projection volume of a cloud atmosphere, properties of the backscattering water particles. The pulse of quasi-optical energy is projected into the divergent projection volume of the cloud atmosphere. The divergent projection volume is defined by an axis of projection and an angle of projection about the axis of projection. The portion of the projected pulse of optical energy backscattered by water particles within the divergent projection volume of the cloud atmosphere is received and detected. Various properties of the backscattering water particles, which can be determined from the detected portion of the projected pulse backscattered by water particles can include particle density and/or particle size.

Measuring cloud metrics using diverging quasi-optical radar

A system and method for detecting hard targets in a free-space laser system includes a laser, an optical detector, and electronics. The laser is configured to emit a laser beam along an optical path through transmitter optics into a field of view. The optical detector is positioned along a laser transmitter path and configured to receive retroreflections of the laser beam. The electronics are configured to determine if an output of the optical detector is indicative of presence of a hard target within the field of view, and control the laser to a safe state if the output is indicative of presence of the hard target.

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Burnsville, MN, United States of America

Mark Ray