FLIR-to-missile boresight correlation and non-uniformity compensation of the missile seeker
First Claim
1. A method of providing target handover from a FLIR to a missile tracker, comprising:
- receiving missile video from the tracker'"'"'s IR imager;
receiving FLIR video from the FLIR;
performing a boresight correlation of the un-NUCed missile video to the FLIR video to align the IR imager to the FLIR; and
performing non-uniformity compensation (NUC) on the missile video.
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Accused Products
Abstract
The present invention provides for simple and streamlined boresight correlation of FLIR-to-missile video. Boresight correlation is performed with un-NUCed missile video, which allows boresight correlation and NUC to be performed simultaneously thereby reducing the time required to acquire a target and fire the missile. The current approach uses the motion of the missile seeker for NUCing to produce spatial gradient filtering in the missile image by differencing images as the seeker moves. This compensates DC non-uniformities in the image. A FLIR image is processed with a matching displace and subtract spatial filter constructed based on the tracked scene motion. The FLIR image is resampled to match the missile image resolution, and the two images are preprocessed and correlated using conventional methods. Improved NUC is provided by cross-referencing multiple measurements of each area of the scene as viewed by different pixels in the imager. This approach is based on the simple yet novel premise that every pixel in the array that looks at the same thing should see the same thing. As a result, the NUC terms adapt to non-uniformities in the imager and not the scene.
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Citations
36 Claims
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1. A method of providing target handover from a FLIR to a missile tracker, comprising:
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receiving missile video from the tracker'"'"'s IR imager; receiving FLIR video from the FLIR; performing a boresight correlation of the un-NUCed missile video to the FLIR video to align the IR imager to the FLIR; and performing non-uniformity compensation (NUC) on the missile video. - View Dependent Claims (2, 3, 4, 5, 6, 7, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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8. The method of claim 8, further comprising keeping track of a variability of the response of the imager pixels in the forward mapping to update the registered sum image, wherein imager pixels that provide the most consistent response contribute most heavily to the registered sum and registered count images, hence the estimate of the input scene
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18. A method of correlating uncompensated IR video to reference video, comprising:
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using the temporal motion of the IR imager over a plurality of frames of IR video to form a first edge map; measuring scene motion in the IR video; spatially processing images in the reference video in accordance with the scene motion to locate at least some of the same edges to form a second edge map; and correlating the first and second edge maps. - View Dependent Claims (19, 20, 21)
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22. A method of enhancing video images, comprising:
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performing non-uniformity compensation (NUC) on a sequence of input images; providing a scene pixel stationarity map for each input image from the NUC; providing a scene motion estimate for each input image from the NUC; for each compensated image, using the scene pixel stationarity map to select a number Ni of images to merge at each scene pixel; using the scene motion estimate to select the most recent N(i,j) contributors at each image pixel (i,j); and creating a composite image by merging the N(i,j) contributors from the compensated images at each image pixel. - View Dependent Claims (23)
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24. A method of non-uniformity compensation (NUC) for a pixilated IR imager, comprising:
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registering a temporal sequence of input images from the IR imager having different FOVs to create an estimate of an input scene; backward mapping the estimated input scene to the different FOVs to create an estimate input image for each; comparing each said estimate input image to the associated input image to estimate pixel-by-pixel response non-uniformity compensation (NUC) terms for the IR imager; and applying the NUC terms to the images to generate compensated images. - View Dependent Claims (25, 26, 27, 28, 29, 30, 31, 32, 33)
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34. A method of non-uniformity compensation (NUC) for a pixilated IR imager, comprising:
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capturing a temporal sequence of input images from the IR imager having different FOVs; compensating each input image with apriori NUC terms if they exist to form compensated images; tracking a FOV motion across the scene; registering and adding the input images together to create a registered sum image; accumulating the number of input images that contribute to each pixel in the scene in a registered count image; dividing the registered sum image by the registered count image to form a registered average image; using the FOV motion to backward map the registered average image to the different FOVs to create an estimated input image for each; differencing respective pairs of compensated images and estimated input images to form a sequence of unexplained difference images; performing an Nth order correlation on said unexplained difference images to form NUC error terms; and combining the NUC error terms with the NUC terms from the previous iteration to update the NUC terms. - View Dependent Claims (35)
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36. A method of non-uniformity compensation (NUC) for a pixilated IR imager, comprising:
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capturing a temporal sequence of input images from the IR imager having different FOVs; compensating each input image with apriori NUC terms to form compensated images; tracking a FOV motion across the scene; registering and adding the input images together to create a registered sum image; accumulating the number of input images that contribute to each pixel in the scene in a registered count image; dividing the registered sum image by the registered count image to form a registered average image; convolving the FOV motion against the registered average image to form an ideal stacked average; comparing the ideal stacked average to a stacked average of the compensated images to form a composite unexplained difference image that is output as the NUC error terms to update the NUC terms; correlating said NUC error terms against the FOV motion trace to form a registered sum error; and adding the registered sum error to the registered sum image to update the registered average image for another iteration on the NUC error terms.
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Specification