BAE Systems Information and Electronic Systems Integration, Inc.
대리인 / 주소
Wolf, Greenfield, &
인용정보
피인용 횟수 :
21인용 특허 :
90
초록▼
One embodiment of the invention is directed to methods and apparatus for determining a variation of a calibration parameter of a pixel of the thermal sensor during operation of the imaging apparatus, after an initial calibration procedure. Another embodiment of the invention is directed to methods a
One embodiment of the invention is directed to methods and apparatus for determining a variation of a calibration parameter of a pixel of the thermal sensor during operation of the imaging apparatus, after an initial calibration procedure. Another embodiment of the invention is directed to methods and apparatus for calculating a gain calibration parameter using first and second ambient temperature values and respective first and second resistance values for a pixel of a sensor. A further embodiment of the invention is directed to calculating an offset calibration parameter for at least one pixel using a gain of the at least one pixel between first and second times and an ambient temperature at a third time, wherein the pixel is exposed to both scene and ambient radiation at the third time.
대표청구항▼
What is claimed is: 1. An imaging apparatus, comprising: a plurality of pixels to detect radiation and to output image signals based on the detected radiation; a temperature sensor to detect an ambient temperature; and means, coupled to the plurality of pixels and the temperature sensor, for determ
What is claimed is: 1. An imaging apparatus, comprising: a plurality of pixels to detect radiation and to output image signals based on the detected radiation; a temperature sensor to detect an ambient temperature; and means, coupled to the plurality of pixels and the temperature sensor, for determining a calibration parameter of a pixel during operation of the imaging apparatus, based on at least a first ambient temperature of the pixel and a second ambient temperature of the pixel, each measured after an initial calibration procedure. 2. The imaging apparatus of claim 1, wherein the means for determining a calibration parameter comprises means for determining an offset of the pixel. 3. The imaging apparatus of claim 1, wherein the means for determining a calibration parameter comprises means for determining a gain of the pixel. 4. The imaging apparatus of claim 1, wherein the means for determining a calibration parameter is actuated to determine the calibration parameter when a predetermined time period has elapsed. 5. The imaging apparatus of claim 1, wherein the means for determining a calibration parameter is actuated to determine the calibration parameter when a predetermined ambient temperature change has occurred. 6. The imaging apparatus of claim 1, wherein the means for determining a calibration parameter comprises at least one processor, and wherein the at least one processor is programmed to perform an act of: calculating an offset calibration parameter for the pixel based on a change in resistance of the pixel over a time period and a change in the ambient temperature of the pixel over the time period. 7. The imaging apparatus of claim 6, wherein the offset calibration parameter is a change in a resistance of the pixel caused by a change in an ambient temperature of the pixel. 8. The imaging apparatus of claim 1, wherein the plurality of pixels are sensitive to radiation in the infrared range. 9. The imaging apparatus of claim 1, wherein the plurality of pixels are sensitive to thermal radiation. 10. The imaging apparatus of claim 1, wherein the means for determining includes means for determining the calibration parameter after an initial calibration procedure during which calibration is performed at only one calibration temperature. 11. A method of calibrating an imaging system comprising a thermal sensor, comprising an act of: determining a calibration parameter of a pixel of the thermal sensor during operation of the imaging apparatus, based on at least a first ambient temperature of the pixel and a second ambient temperature of the pixel, each measured after an initial calibration procedure. 12. The method of claim 11, wherein the act of determining a calibration parameter includes comparing first and second output signals of the pixel. 13. The method of claim 12, wherein the act of determining a calibration parameter further includes comparing first and second temperature signals associated with the first and second output signals. 14. The method of claim 11, wherein the act of determining a calibration parameter includes determining an offset calibration parameter of the pixel. 15. The method of claim 14, wherein the act of determining an offset calibration parameter includes determining a change in resistance of the pixel over a time period and a change in the ambient temperature of the pixel over the time period. 16. The method of claim 11, wherein the act of determining a calibration parameter includes determining a gain calibration parameter of the pixel. 17. The method of claim 11, wherein the act of determining a calibration parameter occurs when a predetermined time period has elapsed. 18. The method of claim 11, wherein the act of determining a calibration parameter occurs when a predetermined ambient temperature change has occurred. 19. The method of claim 11, wherein the act of determining a calibration parameter includes determining a calibration parameter of a pixel sensitive to infrared radiation. 20. The method of claim 11, wherein the act of determining includes determining the calibration parameter after an initial calibration procedure during which calibration is performed at only one calibration temperature. 21. The method of claim 16, wherein the act of determining a gain calibration parameter of the pixel comprises acts of: shielding the pixel from scene radiation at a first time and measuring a resistance of the pixel and an ambient temperature at the first time; shielding the pixel from scene radiation at a second time and measuring a resistance of the pixel and an ambient temperature at the second time; calculating a first gain calibration parameter using the resistance of the pixel and the ambient temperature at the first time and the resistance of the pixel and the ambient temperature at the second time; and determining a second gain calibration parameter for the pixel. 22. The method of claim 21, wherein the act of calculating the first gain calibration parameter includes determining a change in the resistance of the pixel between the first and second times relative to a change in the ambient temperature between the first and second times. 23. The method of claim 22, wherein the act of calculating the first gain calibration parameter further comprises acts of: subtracting the ambient temperature at the first time from the ambient temperature at the second time to generate an ambient temperature difference; subtracting the resistance of the pixel at the first time from the resistance of the pixel at the second time to generate a resistance difference; and dividing the ambient temperature difference by the resistance difference. 24. The method of claim 21, wherein: the act of shielding the pixel from scene radiation at the first time comprises performing a shutter operation at the first time; and the act of shielding the pixel from scene radiation at the second time comprises performing a shutter operation at the second time. 25. The method of claim 21, wherein the act of determining a second gain calibration parameter for the pixel comprises acts of: shielding the pixel from scene radiation at a third time and measuring a resistance of the pixel and an ambient temperature at the third time; and calculating a second gain calibration parameter using the resistance of the pixel and the ambient temperature at the second time and the resistance of the pixel and the ambient temperature at the third time; wherein the method further comprises an act of updating the gain calibration parameter with the second gain calibration parameter. 26. The method of claim 21, wherein the pixel is a first pixel in an array of pixels, and wherein the method further comprises: measuring a resistance of a second pixel in the array of pixel at the first time; measuring a resistance of the second pixel at the second time; and calculating a gain calibration parameter for the second pixel using the resistance of the second pixel at the first and second times and the ambient temperature at the first and second times. 27. The method of claim 21, wherein: the act of measuring the ambient temperature at the first time comprises measuring a substrate temperature at the first time; the act of measuring the ambient temperature at the second time comprises measuring a substrate temperature at the second time; and the act of calculating the first gain calibration parameter comprises calculating the first gain calibration parameter using the resistance of the pixel at the first and second times and the substrate temperature at the first and second times. 28. A method of claim 21, further comprising acts of: receiving scene radiation via the pixel at a third time and measuring an ambient temperature at the third time; calculating a second gain calibration parameter using the ambient temperature at the third time and a predetermined function that relates an ambient temperature change to a gain calibration parameter change; and updating the gain calibration parameter with the second gain calibration parameter. 29. The method of claim 21, wherein the pixel is a first pixel in an array of pixels, and wherein the method further comprises acts of: shielding a second pixel of the array from scene radiation at a first time and measuring a resistance of the second pixel at the first time; shielding the second pixel from scene radiation at a second time and measuring a resistance of the second pixel at the second time; and calculating a gain calibration parameter for the second pixel using the resistance of the second pixel and the ambient temperature at the first time and the resistance of the second pixel and the ambient temperature at the second time. 30. The method of claim 21, further comprising an act of: applying the second gain calibration parameter to correct a gain error of the pixel. 31. The method of claim 30, wherein the act of applying includes applying the second gain calibration parameter to an output signal of the pixel to correct the gain error of the pixel. 32. The method of claim 30, wherein the act of applying includes applying the second gain calibration parameter to an operating parameter of the pixel to correct the gain error of the pixel. 33. The imaging apparatus of claim 1, further comprising: a data storage device to store first and second ambient temperature values and first and second resistance values for each pixel of the plurality of pixels; wherein the means for determining a calibration parameter comprises: means for calculating a first gain calibration parameter for each pixel of the plurality of pixels using the first and second ambient temperature values and first and second resistance values for each pixel of the plurality of pixels; and means for determining a second gain calibration parameter for each pixel of the plurality of pixels. 34. The imaging apparatus of claim 33, further comprising: a shutter mechanism to block scene radiation; wherein the first and second ambient temperature values and first and second resistance values for each pixel of the plurality of pixels are each detected during actuation of the shutter mechanism. 35. The imaging apparatus of claim 33, further comprising: a substrate coupled to the plurality of pixels; wherein the temperature sensor is thermally coupled to the substrate so as to detect a temperature of the substrate. 36. The imaging apparatus of claim 33, wherein the plurality of pixels are sensitive to radiation in the infrared range. 37. The imaging apparatus of claim 33, wherein the plurality of pixels are sensitive to thermal radiation. 38. The imaging apparatus of claim 33, wherein at least some of the plurality of pixels are bolometers. 39. A method of calculating an offset calibration parameter of a pixel of a camera, comprising acts of: determining a gain of the pixel during a period of operation of the camera between first and second times, after an initial calibration procedure; exposing the pixel to both scene and ambient radiation at a third time; measuring an ambient temperature of the pixel at the third time; and calculating the offset calibration parameter of the pixel using the gain of the pixel between the first and second times and the ambient temperature of the pixel at the third time. 40. The method of claim 39, further comprising an act of: determining a portion of a change in temperature of the pixel between the second and third times based solely on a change in scene radiation using the offset calibration parameter and a resistance of the pixel measured at the third time. 41. The method of claim 40, further comprising an act of: determining the portion of a change in temperature of the pixel between the second and third times based solely on a change in scene radiation by multiplying a gain calibration parameter by the resistance of the pixel measured at the third time to generate a product, and adding the offset calibration parameter to the product. 42. The method of claim 39, wherein the act of calculating the offset calibration parameter includes an act of determining the portion of the resistance of the pixel at the third time that is attributable to ambient radiation. 43. The method of claim 39, further comprising acts of: shielding the pixel from scene radiation at the first and second times; and exposing the pixel to ambient radiation and scene radiation at the third time. 44. A method of claim 43, wherein the act of shielding comprises performing a shutter operation at the first and second times. 45. The method of claim 39, wherein the act of determining a gain of the pixel comprises acts of: shielding the pixel from scene radiation at a first time and measuring a resistance of the pixel and an ambient temperature at the first time; shielding the pixel from scene radiation at a second time and measuring a resistance of the pixel and an ambient temperature at the second time; and calculating the gain of the pixel using the resistance of the pixel and the ambient temperature at the first time and the resistance of the pixel and the ambient temperature at the second time. 46. The method of claim 39, wherein the pixel is a first pixel in an array of pixels, and wherein the method further comprises: determining a gain of a second pixel in the array between the first and second times; measuring a resistance of the second pixel; and calculating a change in the resistance of the second pixel between the second time and the third time resulting from a change in the ambient temperature between the second time and the third time. 47. The method of claim 39, wherein: the act of measuring an ambient temperature of the pixel at a third time comprises measuring a substrate temperature at the third time. 48. The method of claim 39, further comprising an act of: applying the offset calibration parameter to an output signal of the pixel at the third time to correct an offset error of the pixel. 49. The method of claim 48, wherein the act of applying includes applying the offset calibration parameter to a resistance of the pixel at the third time to correct the offset error of the pixel. 50. The method of claim 48, wherein the act of applying includes applying the offset calibration parameter to an operating parameter of the pixel to correct the offset error of the pixel. 51. An imaging apparatus, comprising: at least one pixel to detect radiation and to output image signals based on the detected radiation; a temperature sensor to detect an ambient temperature; and means for calculating an offset calibration parameter for the at least one pixel using a gain of the at least one pixel during a period of operation of a camera between first and second times after an initial calibration procedure, and an ambient temperature at a third time, wherein the pixel is exposed to both scene and ambient radiation at the third time. 52. The imaging apparatus of claim 51, further comprising: a substrate coupled to the at least one pixel; wherein the temperature sensor thermally coupled to the substrate so as to detect a temperature of the substrate. 53. The imaging apparatus of claim 51, wherein the at least one pixel is sensitive to radiation in the infrared range.
연구과제 타임라인
LOADING...
LOADING...
LOADING...
LOADING...
LOADING...
이 특허에 인용된 특허 (90)
Wall Llewellyn E. (Concord MA), Analog to digital conversion on multiple channel IC chips.
Wood R. Andrew (Bloomington MN), Camera for producing video output signal, infrared focal plane array package for such camera, and method and apparatus f.
Lillquist Robert D. (Schenectady NY) Pimbley Joseph M. (Schenectady NY) Vogelsong Thomas L. (Schenectady NY), Composite visible/thermal-infrared imaging system.
Sweetser Kevin N. (Garland TX) Beratan Howard R. (Richardson TX) Owen Robert A. (Rowlett TX), Defective pixel signal substitution in thermal imaging systems.
Wang Samuel C. (Liverpool NY) Swab John M. (Baldwinsville NY), Direct coupled charge injection readout circuit and readout method for an IR sensing charge injection device.
Schmidtchen Gerhard (Sachsenheim DEX) Muller Mathias (Oberstenfeld DEX), Electric heating apparatus for regulating the temperature of a plurality of liquids.
Anastassiou Dimitris (Croton-on-Hudson NY) Mitchell Joan L. (Ossining NY), Gray scale image data compression with code words a function of image history.
Grinberg Jan (Los Angeles CA) Balcerak Raymond (Alexandria VA) Wu Chiung-Sheng (Los Angeles CA) Efron Uzi (Los Angeles CA) Braatz Paul O. (Calabasas CA), Infrared transducer and goggles incorporating the same.
Tsang Robert W. K. (Bedford MA) Core Theresa A. (North Andover MA), Method for fabricating monolithic chip containing integrated circuitry and suspended microstructure.
Hanafusa Tsutomu (Sagamihara JPX) Shiraishi Kikuo (Kawasaki JPX), Method of compensating scattered characteristics of outputs of an infrared detector of multiple-element type.
Foss Norman A. (North Oaks MN) Kruse ; Jr. Paul W. (Edina MN) Wood R. Andrew (Bloomington MN), Monolithic integrated dual mode IR/mm-wave focal plane sensor.
Grinberg Jan (Los Angeles CA) Welkowsky Murray S. (Chatsworth CA) Wu Chiung-Sheng (Los Angeles CA) Braatz Paul O. (Canoga Park CA), Radiation detector array using radiation sensitive bridges.
Masarik David M. (Laguna Beach CA) Hayes Robert S. (Lawndale CA) Cheung Frank N. (Agoura CA) Klatt Robert W. (Rancho Palos Verdes CA), Signal processor for infrared camera.
Woolaway ; II James T. (Goleta CA) Spagnolia Joseph A. (Ventura CA) Frye William H. (Goleta CA), Staring IR-FPA with on-FPA adaptive dynamic range control electronics.
Ianni Suzanne G. (Natick MA) Fierke John R. (Southboro MA) Connors Stephen A. (Center Barnstead NH), System for locating failure signals by comparing input data with stored threshold value and storing failure addresses in.
Walker William K. (2605 Westridge Dr. Plano ; Collin County TX 75075) Long John P. (218 Ridgegate Dr. Garland ; Dallas County TX 75040) Owen Robert A. (4105 Tradewind Dr. Rowlett ; Dallas County TX 7, Thermal isolation for hybrid thermal detectors.
Walker William K. (Plano TX) Long John P. (Garland TX) Owen Robert A. (Rowlett TX) Runnels Bert T. (Garland TX) Shelton Gail D. (Mesquite TX), Thermal isolation for hybrid thermal detectors.
Boulanger, Pierre; Elmfors, Per; Högasten, Nicholas; Hoelter, Theodore R.; Strandemar, Katrin; Sharp, Barbara; Kurth, Eric A., Determination of an absolute radiometric value using blocked infrared sensors.
Durand, Alain; Vilain, Michel; Minassian, Christophe, Method for correcting the drift of an infrared radiation detector comprising an array of resistive imaging bolometers and device implementing such a method.
※ AI-Helper는 부적절한 답변을 할 수 있습니다.