Back to results
US 12,754,009 B2Granted
Image-plane self-calibration in interferometry using closed triad imaging
AssigneeAssociated Universties, Inc.
InventorsNithyanandan Thyagarajan, Christopher L. Carilli, Bojan Nikolic
Life of this patent
Estimating the term…
Abstract
A method to derive phase-coherent images with an interferometer, in situations where interferometric phase errors can be factorized into element-based terms (‘piston phases’) is disclosed. The method is preferably implemented completely in the image domain, without resort to aperture plane measurements of visibilities, or element-based voltage complex gains.
Claims18
A method of interferometric self-calibration in the image plane, comprising the steps of:
- initializing a first image model;
- deriving first X and Y shift values for each measured triad images by cross correlation with the first image model;
- shifting a first position of each measured triad image using the first X and Y shift values;
- synthesizing a second image model by summing the first shifted positions of the measured triad images;
- deriving second X and Y shift values for each measured triad image by cross correlation with the second image model;
- shifting a second position of each measured triad image using the second X and Y shift values;
- synthesizing a third image model by summing the second shifted positions of the measured triad images;
- and
- repeating the steps of deriving X and Y shift positions of a preceding synthesized image model, shifting the position of each measured triad image using the X and Y shift values, and synthesizing an additional image model by summing shifted positions of the measured triad images until a convergence point to obtain an image-plane self-calibrated image.
6 more elements
A system for obtaining an image-plane self-calibrated image, comprising:
- an image sensor;
- and
- a processor in communication with the image sensor, wherein the processor:
- obtains a measured triad images from the image sensor;
- is initialized with a first image model of the measured triad images;
- derives first X and Y shift values for each measured triad images by cross correlation with the first image model;
- shifts a first position of each measured triad images using the first X and Y shift values;
- synthesizes a second image model by summing the first shifted positions of the measured triad images;
- derives second X and Y shift values for each measured triad images by cross correlation with the second image model;
- shifts a second position of each measured triad images using the second X and Y shift values;
- synthesizes a third image model by summing the second shifted positions of the measured triad images;
- repeats the steps of deriving X and Y shift positions of a preceding synthesized image model, shifting the position of each measured triad image using the X and Y shift values, and synthesizing an additional image model by summing shifted positions of the measured triad images until a convergence point is reached;
- and
- outputs an image-plane self-calibrated image of the converged image model.
11 more elements
Dependencies are inferred from the claim text.