Lockheed Martin Corporation

Eric H Smith

Richard Lee Kendrick

Gopal Vasudevan

Robert Duncan Reardon

Robert D Sigler

Alan Lee Duncan

David M Stubbs

Kenneth John Triebes

Joseph T Pitman

A method for reducing noise in a multi-aperture imaging system is provided. Each sub-collector of the system, at least one of which has an adjustable optical path length, collects a portion of a wavefront. The adjustable optical path length is varied to each of a set of predetermined lengths to generate interference patterns. Each interference pattern is recorded at an image plane of the system to generate a recorded interference pattern made up of pixels. Pixel intensity data sets are generated, each of which includes a pixel intensity level from a corresponding one of the pixels from each recorded interference pattern. Each pixel intensity data set is Fourier transformed, and in each Fourier transformed data set, spatial frequencies having power values above a predetermined level are identified. The power levels exceeding the threshold are measured and a resultant image is constructed, where each image pixel thereof corresponds to one pixel intensity data set and has one or more intensity values corresponding to the measured power values for that corresponding pixel intensity data set.

Near field suppression with a multi-aperture imaging system

System and method for estimating and correcting an aberration of an optical system. The method includes capturing a first plurality of images on a first plurality of planes. The first plurality of images is formed by at least the optical system. Additionally, the method includes processing at least information associated with the first plurality of images, and determining a first auxiliary function based upon at least the information associated with the first plurality of images. The first auxiliary function represents a first aberration of the optical system. Moreover, the method includes adjusting the optical system based upon at least information associated with the first auxiliary function.

Near field diversity method for estimation and correction of aberrations

A multiple instrument distributed aperture sensor ('MIDAS') science payload system mounted on a spacecraft, including a spacecraft interface ring affixing the MIDAS science payload system to the spacecraft, and a multiple telescope array ('MTA') further including a mechanical subsystem further including an optical bench, an optical subsystem mounted upon the mechanical subsystem collecting light and merging the light into a passive, actively-sensed or hyperspectral image, and a laser subsystem providing laser illumination for collecting active remote sensing data. The MIDAS science payload system also includes a hexapod in physical communication with and between the spacecraft interface ring and the mechanical subsystem. The MIDAS science payload system further includes a plurality of launch locks affixed to the spacecraft interface ring supporting the MTA in a stowed configuration, and a plurality of science instruments (&#x201c;SIs&#x201d;) mounted on the mechanical subsystem obverse to the optical subsystem, individually and concurrently sensing the passive, actively sensed or hyperspectral image.

Enhanced multiple instrument distributed aperture sensor

A method of restoring low spatial frequency spectral information to an image using a Fizeau Fourier transform spectrometer ('FFTS') system is provided. Portions of a wavefront collected by the FFTS are interfered. The interference patterns are Fourier transformed to generate spectral images. A region of the image is identified, for which spectral information is predetermined. Object estimates are generated, each of which corresponds to a spectral image. Each object estimate is iteratively adjusted applying a system spectral optical transfer function ('SOTF') to it and modifying it until a match is made with the corresponding spectral image. Each adjusted object estimate is then iteratively restored by applying a system optical transfer function (&#x201c;OTF&#x201d;) to it and then applying a DC bias to it until a match is made between the identified region in the sum of the object estimates and the identified region of a measured panchromatic object image.

Enhanced recovery of low spatial frequency spectral information in a Fizeau Fourier transform spectrometer

A Fourier Transform Spectrometer ('FTS') system includes a Fizeau FTS having a plurality of sub-collecting elements, adjacent ones of which are separated by a gap distance, and at least one of which has an adjustable optical path. The FTS system further includes a Michelson FTS having an adjustable optical path. The FTS system further includes one or more processors configured to select spectral data collected by the Fizeau FTS corresponding to spatial frequencies for which the Fizeau FTS has a modulation transfer function ('MTF') value above a first threshold level, to select spectral data collected by the Michelson FTS corresponding to spatial frequencies for which the Michelson FTS has a MTF value above a second threshold level, and to combine the selected spectral data from the Fizeau FTS with the selected spectral data from the Michelson FTS.

Restoration of Fizeau FTS spectral data using low and/or zero spatial resolution Michelson FTS data

Detecting the presence of a target material in a scene by using a multi-aperture interferometer system having a plurality of apertures at least one of which has an adjustable optical path length, by adjusting the aperture(s) to obtain a predetermined optical path length difference among the apertures, the predetermined optical path length difference being based on a source laser wavelength and a target material wavelength, illuminating the scene with the source laser, capturing a spectral data set corresponding to an interference pattern generated in the multi-aperture interferometer system for an illuminated point source in the scene, the spectral data set containing spatially distributed spectral data, and determining whether the target material is present at the illuminated point source based on a presence of spectral data in at least one side lobe of the spectral data set.

Generation of spatially distributed spectral data using a multi-aperture system

A spectrometer that implements the functionality of a Fizeau interferometer, the spectrometer including a collection device that is configured to collect a wavefront, a deformable mirror disposed at an image plane of the collection device, the deformable mirror having a plurality of sections, at least one of which is deformed to form interference patterns on the wavefront at the image plane, and a Fourier transformation module configured to derive spectral information from the interference patterns.

Fourier transform spectrometry with a single-aperture interferometer

A method for reducing a piston between a plurality of optical-collection devices configured to operate as a single optical device, such that the optical-collection devices are configured to capture select portions of a wavefront. The method includes pistoning an adjustable-optical path of at least one of the optical-collection devices through a plurality of steps; collecting a set of focused images and a set of defocused images for each step; Fourier transforming the first and second sets of images to generate respective first and second sets of spectral information for the wavefronts; deriving a set of wavefront errors based on the first and second sets of spectral information using a phase diversity algorithm; and deriving a piston value for the piston from the wavefront errors using a multi-color interferometry algorithm.

Phase diversity method and apparatus using fourier transform spectroscopy

A spectrometer configured to extract spectral information from a wavefront. The spectrometer includes a first collection device that includes an adjustable-optical path and configured to collect a first portion of a wavefront; a second collection device configured to collect a second portion of the wavefront; combiner optics configured to interfere the first and second portions of the wavefront at an image plane of the first and second collector devices to form interference patterns at the image plane; and a Fourier transformation module configured to derive spectral information from the interference patterns.

Fourier transform spectrometry with a multi-aperture interferometer

A method is provided for reducing the piston of neighboring first and second surfaces illuminated by polychromatic light transmitted from an unresolved-light source such that light transmitted or reflected from the first surface is out of phase with light respectively transmitted or reflected from the second surface, and the out-of-phase light is passed through a grism that generates a fringe pattern in the far-field. According to one exemplary embodiment, the method includes Fourier transforming the fringe pattern to generate a two-dimensional (2D) power spectrum; generating the absolute value of the 2D power spectrum to form an absolute value representation; displaying the 2D the absolute value representation on a computer display; and reducing the piston to affect rotation of the absolute value representation on the computer display and approximately align a central axis of the absolute value representation with an axis that indicates approximate alignment of the first and second surfaces.

Method and apparatus for estimating piston using a grism

Embodiments of the present invention are directed to a nuller that is used to significantly reduce or eliminate a monochromatic radiation signal within a polychromatic object field. In one embodiment, a method of nulling a coherent light from a light beam having the coherent light and an incoherent light comprises collimating the light beam having the coherent light and the incoherent light, and destructively interfering the coherent light to null the coherent light with no destructive interference of the incoherent light so as to project the incoherent light without the coherent light.

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San Jose, CA, United States of America

Eric H Smith