Abstract:
A system includes a first sensor (102) positioned to sense presence of a contrail in a first volume (104), wherein the first volume at least partially overlaps an expected volume of a contrail (106) proximate an aircraft. A second sensor (108) is positioned to sense a background reference in a second volume (110), where the second volume (110) does not overlap the expected volume of a contrail (106) proximate an aircraft. A controller (118) is operatively connected to the first and second sensors (102, 108). The controller (118) includes machine readable instructions configured to cause the controller (118) to utilize data input from both the first and second volumes (104, 110) to determine if a contrail is present from the aircraft. A system includes machine readable instructions configured to cause the controller (118) to predict persistence of contrails on an intended route through the volume of airspace and to determine an improved route and/or propulsion operation to reduce contrail formation and persistence relative to the intended route.
Abstract:
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 (26) 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 (36H, 36L), each having a different gain. A ratio of the gains of the first and second detector (36H, 36L) 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.
Abstract:
The method according to the invention includes receiving, over an aircraft data communications bus, a plurality of non-pneumatic inputs corresponding to aircraft operational parameters. The method further includes processing the plurality of non-pneumatic inputs through an artificial intelligence network to generate an air data output value, and outputting the air data output value to a consuming system for use when a pneumatic-based air data output value is determined to be unreliable.
Abstract:
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.
Abstract:
Apparatus and associated methods relate to determining metrics of water particles in clouds by directing light pulses at a cloud and measuring a peak, a post-peak value and a high-frequency fluctuation of light signals reflected from the cloud. The light pulses include: a first pulse having circularly polarized light of a first wavelength; and a second pulse of a second wavelength. The reflected light signals include: a first reflected light signal having left-hand circular polarization of the first wavelength; a second reflected light signal having right-hand circular polarization of the first wavelength; and a third reflected light signal of the second wavelength. An extinction coefficient and a backscatter coefficient are determined based on the measured peak and post-peak slopes of the first and second reflected light signals. The measured high-frequency fluctuations of the three reflected light signals can be used to calculate cloud particle sizes.
Abstract:
Apparatus (22) and associated methods relate to predicting failure and/or estimating remaining useful life of an air-data-probe heater. Failure is predicted or useful life is estimated based on an electrical metric of the electrical operating power provided to a resistive heating element (24) of the air-data-probe heater. The electrical metric of the air data probe heater is one or more of: i) phase relation between voltage across the resistive heating element and leakage current, which is conducted from the resistive heating element to a conductive sheath surrounding the resistive heating element; ii) a time-domain profile of leakage current through the heating element insulation during a full power cycle; and/or iii) high-frequency components of the electrical current conducted by the resistive heating element and/or the voltage across the resistive heating element.
Abstract:
Apparatus and associated methods relate to determining a size and/or density of Super-cooled Large Droplets (SLDs) in a cloud atmosphere by comparing detected optical signals reflected from small and large sampling volumes of a cloud atmosphere. In some embodiments, an optical pulse is generated and divergently projected from a first optical fiber. A collimating lens (30) is aligned within the divergently projected optical pulse collimating a portion thereof. The collimated and uncollimated portions of the optical pulse are projected into the small and large sampling volumes of the cloud atmosphere, respectively. The ratio of the collimated to the uncollimated portions can be optically controlled. Signals corresponding to optical pulses having different collimated/uncollimated ratios are backscattered by the cloud atmosphere, detected and compared to one another. A processor is configured to calculate, based on scintillation spike differences between the optical pulses of different collimated/uncollimated ratios, a size and/or density of SLDs.
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 (12). 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:
Apparatus and associated methods relate to predicting failure and/or estimating remaining useful life of an air-data-probe heater. Failure is predicted or useful life is estimated based on an electrical metric of the electrical operating power provided to a resistive heating element (24) of the air-data-probe heater. The electrical metric of the air data probe heater is one or more of: i) phase relation between voltage across the resistive heating element (24) and leakage current, which is conducted from the resistive heating element (24) to a conductive sheath (36) surrounding the resistive heating element (24); ii) a time-domain profile of leakage current through the heating element insulation during a full power cycle; and/or iii) high-frequency components of the electrical current conducted by the resistive heating element (24) and/or the voltage across the resistive heating element (24).
Abstract:
An optical ice detector and airspeed probe includes an ice detection module (40) and an airspeed module (42). The ice detection module detects the presence or absence of ice, water, or ice and water particles, and the airspeed module determines a line-of-sight speed along a directional vector, each based on backscatter light returns emitted from a common collimated light source. An electronics module (78) determines an airspeed of an aircraft based on the line-of-sight speed determined by the airspeed module and at least one aircraft parameter received from the air data system.