Abstract: A method for detecting and determining a location of an overheat condition includes producing a narrowband optical signal with a laser source and optical pulse generator. The optical signal is sent into the optical fiber. A plurality of reflected optical signals is received. Reflection intensities are detected using a photodetector. The reflection intensities are compared with a triggering threshold. Response times of the reflected optical signals are recorded whenever the reflection intensity of the optical signals is greater than the triggering threshold. The narrowband optical signal is adjusted to another wavelength. An anomaly reflected optical signal is identified using a characteristic of the timings obtained through a range of wavelengths. The location of the overheat condition recorded response times is calculated. The location and existence of the overheat condition is communicated.

Abstract: 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.

Abstract: Overheat and fire detection for aircraft systems includes an optical controller and a fiber optic loop extending from the optical controller. The fiber optic loop extends through one or more zones of the aircraft. An optical signal is transmitted through the fiber optic loop from the optical controller and is also received back at the optical controller. The optical controller analyzes the optical signal to determine the temperature, strain, or both experienced within the zones.

Abstract: A method can include generating reference image data representing a field of view of an interior of a fuel tank, and generating active image data representing the field of view of the interior of the fuel tank when the fuel tank contains fuel. The method can further include producing, by a processing device, a fuel measurement value representing an amount of fuel contained in the fuel tank based on the reference image data and the active image data, and outputting, by the processing device, an indication of the fuel measurement value.

Abstract: A system configured to monitor a plurality of zones of an aircraft includes a line replaceable unit, a first interrogator, and a controller. The line replaceable unit includes first and second connectors in optical communication and an optical fiber. The optical fibers includes a first plurality of fiber Bragg gratings and a plurality of calibration fiber Bragg gratings in a pattern providing information related to a calibration value based upon a center wavelength of each of the first plurality of fiber Bragg gratings. The first interrogator is connected to the line replaceable unit at the first end of the optical fiber and is configured to provide a first optical signal and to receive a first optical response signal from the optical fiber. The controller is operatively connected to the first interrogator and is configured to determine the calibration value of the line replaceable unit.

Abstract: A system configured to monitor temperature in a plurality of zones of an aircraft includes an optical fiber with first and second ends, first and second connectors, and a first interrogator. The optical fiber includes a plurality of fiber Bragg gratings disposed in the optical fiber. The first connector is disposed on the first end of the optical fiber and the second connector is disposed on the second end of the optical fiber. The first interrogator is connected to the first connector and includes an optical switch. The optical switch is in optical communication with the first connector of the optical fiber and is configured to selectively block transmission of the optical signal to the optical fiber.

Abstract: A system configured to a plurality of zones of an aircraft includes first and second connectors are in optical communication, an optical fiber, a first interrogator, and a controller. The optical fiber extends between the first and second connectors and includes a first timing fiber Bragg grating disposed in the optical fiber at a reference location of the optical fiber. The first interrogator is connected to the optical fiber and is configured to provide a first optical signal to the optical fiber and to receive a first timing signal from the optical fiber. The first timing fiber Bragg grating is configured to provide the first timing signal with information related to the first timing fiber Bragg grating from the first interrogator. The controller is operatively connected to the first interrogator and is configured to determine the reference location of the optical fiber.

Abstract: A method can include illuminating an interior of a fuel tank with one or more light pulses, and receiving reflected returns of the one or more light pulses at a light sensor array. The method can further include producing, by a processing device, three-dimensional image data of the interior of the fuel tank based on the received reflected returns, producing, by the processing device, a fuel measurement value representing an amount of fuel contained in the fuel tank based on the three-dimensional image data, and outputting, by the processing device, an indication of the fuel measurement value.

Abstract: 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.

Abstract: A system for an aircraft includes an optical sensor, at least one aircraft sensor, and a controller. The optical sensor is configured to emit a laser outside the aircraft, and the at least one aircraft sensor is configured to sense at least one aircraft condition. The controller is configured to determine a first operational state of the aircraft based upon the at least one aircraft condition and determine a second operational state of the aircraft based on the at least one aircraft condition, and operate the optical sensor to emit the laser at a first intensity during the first operational state and a second intensity during the second operational state, wherein the second intensity is greater than the first intensity.

Abstract: A laser sensing system includes an emitter configured to emit a laser, and a controller. The intensity of the laser is based upon power provided to the laser sensing system. The controller is configured to control the power provided to the laser sensing system, obtain feedback parameters indicative in part of molecular content of the atmosphere, and control the power provided to the laser sensing system based upon the feedback parameters.

Abstract: 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.

Abstract: Apparatus and associated methods relate to projecting a light beam onto an interior surface of an aircraft window so as to indicate a testing location to test for ice accretion. The testing location is determined, by a boundary locator, based on aircraft flight conditions, aircraft exterior shape, and a predetermined size of super-cooled droplets, which could present a hazard to the aircraft. The determined test location corresponds to a calculated boundary that separates locations where super-cooled water droplets of the predetermined size cause ice-accretion from locations where such particles do not cause ice accretion, for such aircraft flight conditions. The light beam is then projected onto the interior surface of the aircraft window at the determined test location. The projected beam of light can indicate, to an observer and/or a detector, a location to monitor for ice accretion caused by super-cooled water droplets of the predetermined size.

Abstract: Overheat and fire detection for aircraft systems includes an optical controller and a fiber optic loop extending from the optical controller. The fiber optic loop extends through one or more zones of the aircraft. An optical signal is transmitted through the fiber optic loop from the optical controller and is also received back at the optical controller. The optical controller analyzes the optical signal to determine the temperature, strain, or both experienced within the zones.

Abstract: A method can include emitting, from a light source, directional light through fuel contained in a fuel tank, and determining a refraction angle of the directional light after the directional light passes through an interface with the fuel. The method can further include determining, by a processing device, an index of refraction of the fuel based on the determined refraction angle, and determining, by the processing device, a density of the fuel based on the determined index of refraction of the fuel.

Abstract: A first air data system for providing first aircraft air data parameter outputs is formed by a first electronics channel of a first multi-function probe (MFP) that is electrically coupled with a first electronics channel of a second MFP to receive static pressure data from the second MFP. A second air data system for providing second aircraft air data parameter outputs is formed by a second electronics channel of the second MFP that is electrically coupled with a second electronics channel of the first MFP to receive static pressure data from the first MFP. A third air data system for providing third aircraft air data parameter outputs is formed by a laser air data sensor that is configured to emit directional light into airflow about the aircraft exterior and to generate the third aircraft air data parameter outputs based on returns of the emitted directional light.

Abstract: A method can include generating image data of an interior of a fuel tank disposed within a wing of an aircraft, and determining, by a processing device, an amount of wing bending of the wing of the aircraft based on the generated image data of the interior of the fuel tank. The method can further include producing, by the processing device, a fuel measurement value representing an amount of fuel contained in the fuel tank based on the amount of wing bending of the wing of the aircraft, and outputting, by the processing device, an indication of the fuel measurement value.

Abstract: A method can include transmitting, from a light source, light through a fuel tank ullage, and determining, by a processing device, an amount of absorption of at least one wavelength of the transmitted light. The method can further include determining, by the processing device based on the amount of absorption of the at least one wavelength of the transmitted light, a chemical composition of the fuel tank ullage.

Abstract: 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.

Abstract: 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.