초록 ▼

Onboard systems and methods for detection of airborne volcanic ash. One or more cameras are added to an aircraft. Each camera is configured to view a volume of air illuminated by a standard aircraft light, such as a strobe warning light (e.g., located on a wing tip) or a forward-facing landing light

Onboard systems and methods for detection of airborne volcanic ash. One or more cameras are added to an aircraft. Each camera is configured to view a volume of air illuminated by a standard aircraft light, such as a strobe warning light (e.g., located on a wing tip) or a forward-facing landing light (e.g., located in the nose). Each camera is connected to a data processor. When diffuse volcanic ash is present, it scatters light transmitted from the standard aircraft light. Each camera converts impinging backscattered light into digital data which is sent to the processor. The processor processes the data from the camera or cameras to derive a measurement of the backscattered light and issues an alert when the amount and type of backscatter are compatible with the presence of volcanic ash.

대표청구항 ▼

1. A method for automatically detecting the presence of airborne particles outside an aircraft during flight, comprising the following steps: (a) placing a camera inside the aircraft with its field of view directed toward a volume that receives light radiation from a standard aircraft light mounted

1. A method for automatically detecting the presence of airborne particles outside an aircraft during flight, comprising the following steps: (a) placing a camera inside the aircraft with its field of view directed toward a volume that receives light radiation from a standard aircraft light mounted to the aircraft;(b) activating the aircraft light;(c) using the camera to convert impinging light radiation into electronic image data of respective images captured when the aircraft light is activated and when the aircraft light is not activated;(d) determining whether said electronic image data is compatible with the presence of volcanic ash in said volume;(e) issuing an activation signal in response to a determination that said electronic image data is compatible with the presence of volcanic ash in said volume; and(f) generating a perceptible alarm in response to issuance of said activation signal,wherein operations (d) and (e) are performed by a computer. 2. The method as recited in claim 1, wherein step (d) comprises applying different statistical weights to the electronic image data of each image, wherein said different statistical weights are a function of a beam pattern emitted by the aircraft light. 3. The method as recited in claim 2, wherein the aircraft light is mounted to a wing tip of the aircraft, further comprising the step of adjusting the statistical weights as a function of displacement of the wing tip. 4. The method as recited in claim 1, wherein step (d) comprises removing electronic image data representing point sources of light visible in an image. 5. The method as recited in claim 1, wherein step (d) comprises: comparing the electronic image data for successive images respectively captured when the aircraft light is and is not activated; anddetermining whether the difference between the electronic image data for successive images exceeds a threshold. 6. The method as recited in claim 1, wherein step (c) is performed multiple times and step (d) comprises: (i) integrating the intensity of multiple images captured when the aircraft light is activated;(ii) integrating the intensity of multiple images captured when the aircraft light is not activated;(iii) comparing the integrated intensity derived by step (i) to the integrated intensity derived by step (ii); and(iv) determining whether the difference between those successive images exceeds a threshold. 7. The method as recited in claim 1, further comprising the steps of carrying a hand-portable unit onboard the aircraft, the hand-portable unit comprising the camera and a processor, wherein the processor performs steps (d) and (e). 8. An aircraft comprising: (a) a standard aircraft light that emits light radiation toward a volume external to the aircraft;(b) a camera inside the aircraft with its field of view directed toward said volume, wherein said camera converts impinging light radiation into electronic image data of respective images captured when the aircraft light is activated and when the aircraft light is not activated;(c) a controller for activating the aircraft light;(d) a processor programmed to determine whether said electronic image data is compatible with the presence of volcanic ash in said volume and issue an activation signal in response to a determination that said electronic image data is compatible with the presence of volcanic ash in said volume; and(e) an output device that generates a perceptible alarm in response to issuance of said activation signal. 9. The aircraft as recited in claim 8, wherein the aircraft light is mounted to a wing tip of the aircraft. 10. The aircraft as recited in claim 8, wherein the aircraft light is mounted to a nose of the aircraft. 11. The aircraft as recited in claim 8, wherein the aircraft light is a strobe light. 12. The aircraft as recited in claim 8, wherein the aircraft light is a landing light. 13. The aircraft as recited in claim 8, wherein said controller sends a synchronization signal to said processor when the aircraft light is activated, and said processor sends an image capture signal to said camera in response to said synchronization signal. 14. The aircraft as recited in claim 8, wherein said processor captures a sequence of electronic images from said camera at fixed time intervals, computes a Fourier transform of the intensity of said images, selects the phase and frequency yielding the greatest integrated intensity as the phase and frequency of the aircraft light being activated, and selects the phase and frequency yielding the smallest integrated intensity as the phase and frequency of the aircraft light being inactivated. 15. The aircraft as recited in claim 8, wherein said processor is further programmed to apply different statistical weights to the electronic image data of each image, wherein said different statistical weights are a function of a beam pattern emitted by the aircraft light. 16. The aircraft as recited in claim 15, wherein the aircraft light is mounted to a wing tip of the aircraft, and said processor is further programmed to adjust the statistical weights as a function of displacement of the wing tip. 17. The aircraft as recited in claim 8, wherein said processor is further programmed to remove electronic image data representing point sources of light visible in an image. 18. The aircraft as recited in claim 8, wherein said processor is further programmed to compare the electronic image data for successive images respectively captured when the aircraft light is and is not activated, and then determine whether the difference between the electronic image data for successive images exceeds a threshold. 19. The aircraft as recited in claim 8, wherein said processor is further programmed to: (i) integrate the intensity of multiple images captured when the aircraft light is activated;(ii) integrate the intensity of multiple images captured when the aircraft light is not activated;(iii) compare the integrated intensity derived by step (i) to the integrated intensity derived by step (ii); and(iv) determine whether the difference between those successive images exceeds a threshold. 20. A method for automatically detecting the presence of airborne particles outside an aircraft during flight, comprising the following steps: (a) emitting light radiation toward a volume external to the aircraft;(b) converting light radiation backscattered from said volume into electronic image data of respective images, said images being captured at different times;(c) processing said electronic image data to derive the amount of backscattered light radiation and the rate of change of said amount;(d) determining whether said amount and said rate of change are compatible with the presence of volcanic ash in said volume;(e) issuing an activation signal in response to a determination that said amount and said rate of change are compatible with the presence of volcanic ash in said volume; and(f) generating a perceptible alarm in response to issuance of said activation signal,wherein operations (c) through (e) are performed by a computer. 21. The method as recited in claim 20, wherein said emitted light radiation is emitted by a standard aircraft light such as a landing light or a strobe light. 22. A method for automatically detecting the presence of airborne particles outside an aircraft during flight, comprising the following steps: (a) emitting light radiation toward a volume external to the aircraft when said volume contains a safe level of or no volcanic ash particles;(b) converting light radiation backscattered from said volume into electronic image data of a reference image;(c) after steps (a) and (b) have been performed, emitting light radiation toward said volume;(d) converting light radiation emitted in step (c) and backscattered from said volume into electronic image data of a non-reference image;(e) comparing said electronic image data of said reference and non-reference images;(f) determining whether the difference between said reference and non-reference images exceeds a threshold;(g) issuing an activation signal in response to a determination that said difference exceeds said threshold; and(h) generating a perceptible alarm in response to issuance of said activation signal,wherein operations (e) through (g) are performed by a computer.