Patent Description:
Precision guided munitions can use terminal-imaging seekers to improve weapon effectiveness. Munitions manufacturers are ever developing smaller and higher-shock-tolerant munitions. Therefore, smaller and higher-shock-tolerant terminal-imaging seekers ae being sought. Many munitions have tapered nose cones so as to have a high ballistic coefficient. Terminal-imaging seekers are often located in these tapered nose cones. The terminal-imaging seekers must be able to survive the launch shocks of the munitions in which they are located. Terminal-imaging seekers include an imaging system that traditionally have a lens stack, which can be relatively heavy and big, thereby adding weight and size to the munitions for which they are designed. The available space in munitions for lenses is limited as the nose cones can be tapered for aerodynamic considerations. Furthermore, traditional lenses can be heavy and brittle which can make them have lower mechanical robustness in high shock environments such as in precision guided munitions. What are needed are systems and methods that reduce the size and/or weight of a terminal-imaging seeker. Image seeking systems are disclosed in <CIT>, <CIT>, <CIT> and <CIT>.

Apparatus and associated methods relate to a system for creating a corrected image of a scene for a terminal-imaging seeker as defined in claim <NUM>.

Also provided is a method for creating a corrected image of a scene for a terminal-imaging seeker as defined by claim <NUM>.

Apparatus and associated methods relate to creating corrected images of a scene for a terminal-imaging seeker using an electrically-controllable coded-aperture mask pattern. The coded-aperture mask pattern includes a plurality of pinhole-like apertures - pinhole-like transparent regions or apertures, which can be surrounded by opaque or reflective regions, each of which is configured to perform pinhole-like lensing of the scene. The plurality of pinhole-like apertures form a multiplex of overlapping images on a focal plane array aligned with the optical axis. An image processor reconstructs, based on a configuration of the plurality of pinhole-like apertures and the multiplex of overlapping images, a single image of the scene.

<FIG> are cross-sectional views of two different systems for creating images of a scene for a terminal-imaging seeker. In <FIG>, prior art terminal-imaging seeker <NUM> includes lens stack <NUM>, focal plane array <NUM>, imaging board <NUM>, and video processing card <NUM>, each aligned along optical axis <NUM>. In the depicted embodiment, lens stack <NUM> includes blunt faceplate <NUM>, and a plurality of lenses 24A-24E. Optical lens stack <NUM> is configured to receive light from a scene aligned along optical axis <NUM> and to focus the received light onto focal plane array <NUM>, thereby forming an image of the aligned scene. The formed image includes pixel data generated by the plurality of pixels. Imaging board <NUM> receives the pixel data generated by focal plane array <NUM> and performs image processing operations using the received pixel data. The depicted embodiment has video processing card <NUM>, which receives each of the processed images, and then outputs each received image in a video stream and/or a targeting vector for the munition to seeker <NUM> belongs.

In the embodiment depicted in <FIG>, the lens stack or optical assembly is the most volumetric element of terminal-imaging seeker <NUM>. Axial length LSEEKER of terminal-imaging seeker <NUM> includes axial length LOPTICS of lens stack <NUM> and axial length LELEC of the electronics, which include focal plane array <NUM>, imaging board <NUM>, and video processing card <NUM>. In the depicted embodiment, axial length LOPTICS of lens stack <NUM> is typically greater than <NUM>% of axial length LSEEKER of terminal-imaging seeker <NUM>. Axial length LOPTICS of lens stack <NUM> is also greater than a lateral width WFPA of focal plane array <NUM>.

In <FIG>, terminal-imaging seeker <NUM> includes blunt window faceplate <NUM>, focal plane array <NUM>, imaging board <NUM>, and video processing card <NUM>, but instead of lens stack <NUM>, terminal-imaging seeker <NUM> includes spatial light modulator <NUM> functioning as a spatial light modulator. Comparing <FIG> to one another, a stark difference in axial length LSEEKER is discernable. Although axial length LELEC of the electronics remains the same, in the <FIG> embodiment, axial length LOPTICS of terminal-imaging seeker <NUM> is less than lateral width WFPA of focal plane array <NUM>. By replacing lens stack <NUM> with spatial light modulator <NUM>, a dramatic decrease in system volume can be achieved. Such a replacement can be made if terminal-imaging seeker <NUM> can create images of the scene aligned along optical axis <NUM> that have sufficient quality for use in target detection.

Such sufficient quality imaging can be obtained using spatial light modulator <NUM> functioning as a spatial light modulator. Spatial light modulators extend the concept of a pinhole camera. Spatial light modulators have a plurality of pinhole-like apertures - pinhole-like transparent regions, each of which can be surrounded by opaque or reflective regions or separated from one another by intervening opaque or reflective regions. Each of these pinhole-like apertures is configured to facilitate generation of an image of the scene aligned along the optical axis. Each of these images of the scene is overlapping but shifted in space. The result of this plurality of pinhole-like apertures is a raw super-imposed image that includes a multiplex of overlapping images. A single image of the scene can be reconstructed from the multiplex of overlapping images using one of a variety of reconstruction algorithms. Each reconstruction algorithm corresponds to a specific configuration of the plurality of pinhole-like apertures. Various configurations of the plurality of pinhole-like apertures lend themselves to various corresponding algorithms. Some specific configurations of the pinhole-like apertures correspond to reconstruction algorithms that are less process intensive than other reconstruction algorithms for other specific configurations of pinhole-like apertures. For example, configurations known as separable doubly-Toeplitz configurations can have reconstruction algorithms that are relatively efficient, even for images formed by a large number of pixels.

Spatial light modulator <NUM> is configured to generate a plurality of different coded-aperture mask patterns, each having a plurality of pinhole-like transparent regions separated from one another by intervening opaque and/or reflective regions. Spatial light modulator <NUM> has a plurality of electrically-controllable elements, each configured to modulate light transmission therethrough in response to an electrical control signal. Spatial light modulator <NUM> can be aligned along the optical axis so as to transmit light through the plurality of pinhole-like transparent regions onto the imaging region of focal plane array <NUM> thereby forming a raw super-imposed image of a corresponding plurality of overlapping images of the scene.

According to the claimed subject-matter, the spatial light modulator has a plurality of liquid-crystal elements. The spatial light modulator <NUM> includes two layers of liquid-crystal elements. A first layer is configured to controllably modulate light transmission in parallel lines perpendicular to the optical axis. A second layer is configured to controllably modulate light transmission in parallel lines perpendicular to both the optical axis and the parallel lines of the first layer. Such first and second layer alignment can be done so as to align the parallel lines with the pixels of focal plane array <NUM>. In other embodiments not according to the claimed subject-matter, the spatial light modulator <NUM> can include a two-dimensional array of liquid-crystal pixel elements, the two-dimensional array being perpendicular to the optical axis. Again, alignment of the two-dimensional array can be done so as to be aligned with the pixels of focal plane array <NUM>.

These and other configurations of such liquid-crystal elements can be used to generate various configurations of coded-aperture mask patterns, such as, for example, Uniformly Redundant Array (URA), Modified Uniformly Redundant Array (MURA), Maximum Length Sequence (MLS), and Doubly Toeplitz mask patterns.

Spatial light modulator <NUM> can generate a variety of coded-aperture mask patterns in response to a corresponding variety of control signals. Such capability of generating different coded-aperture mask patterns can be used for various purposes. For example, multiple images obtained by focal plane array <NUM> corresponding to multiple different coded-aperture mask patterns can be used to obtain a corrected image of the scene having fewer aberrations than a corrected image using just one coded-aperture mask pattern. More benefits of such spatial light modulator capability will be further explored below.

Because a spatial light modulator performs the function of a lens, no additional non-optically neutral lens is needed in the system. Because the <FIG> embodiment uses spatial light modulator <NUM> functioning as a spatial light modulator instead of using a lens stack, the <FIG> embodiment can be called a reduced-height design. Because a non-optically neutral lens is not need an optically-neutral lens or window can be used to protect transmit light from the field of view while providing protection for the seeker. The simplest optically neutral lens is simply a flat plate of glass. Such a flat plate of glass can be a viable alternative design when aerodynamic loading is not an issue.

<FIG> are schematic views of an imaging system for a terminal-imaging seeker depicting a juxtaposition of a spatial light modulator and a focal plane array. In <FIG>, terminal-imaging seeker <NUM> (depicted in <FIG>) is reproduced for the purpose of illustrating configurations and details of spatial light modulator <NUM> and focal plane array <NUM>. In <FIG>, sections of spatial light modulator <NUM> and focal plane array <NUM> are shown in cross-sectional magnification. Individual apertures <NUM> of spatial light modulator <NUM> are shown. Also shown are individual pixels <NUM> of focal plane array <NUM>. Spatial light modulator <NUM> and focal plane array <NUM> are axially separated one from another by axial separation distance DSEP. Axial separation distance DSEP, as depicted in <FIG>, is the axial distance between a rear surface of spatial light modulator <NUM> and a front surface of focal plane array <NUM>.

As indicated in the depicted embodiment, axial separation distance DSEP is relatively small, with respect to many other dimensions of terminal-imaging seeker <NUM>. For example, axial separation distance DSEP can be <NUM> microns or less. In some embodiments, axial separation distance DSEP is less than <NUM> times a lateral width dimension of each of pixels <NUM>. Note also the dimensions of a lateral width dimension of individual apertures <NUM>. Such lateral width dimensions can vary between individual apertures <NUM>. In some embodiments, the lateral width dimension of each individual aperture <NUM> is an integral multiple of a minimum lateral width dimension. The minimum lateral width dimension can be less than three times the lateral width dimension of a lateral width dimension of a pixel, for example.

In <FIG>, an axial plan view of spatial light modulator <NUM> is shown. Spatial light modulator <NUM> has been configured to operate as a coded aperture plate in response to a control signal. The coded aperture plate operates as a mask that includes a plurality of apertures <NUM> of various sizes and aspect ratios. Each of the plurality of apertures <NUM> can be used, in pinhole camera fashion, to form an image upon focal plane array <NUM>. By forming a multiplex of pinhole camera-like images, signal strength can be increased over a single pinhole-camera-like image. The signal strength increase comes at the expense of forming a multiplex of overlapping images, from which a single image can be formed using a reconstruction algorithm. Such a reconstruction algorithm can be performed using digital post processing, for example. The reconstruction algorithm selected depends on the configuration of the plurality of pinhole-like apertures <NUM> of spatial light modulator <NUM>.

<FIG> is a schematic view depicting a method of reconstructing an image of a scene from a raw super-imposed image created using a spatial light modulator. In <FIG>, both terminal-imaging seekers <NUM> and <NUM> depicted in <FIG>, respectively, are shown. Terminal-imaging seeker <NUM> produces raw image <NUM>, which is not a multiplex of overlapping images, and therefore does not require reconstruction. Terminal-imaging seeker <NUM> produces raw super-imposed image <NUM>, which is formed as an image containing multiple overlapping exposures of the scene.

Reconstructed image <NUM> is formed using a reconstruction algorithm that is known in the art. For example, <NPL>, the entire disclosure of which is hereby incorporated by reference. Reconstruction of image <NUM> is based on the specific configuration of the plurality of apertures <NUM> created by spatial light modulator <NUM> and based on super-imposed image data <NUM>. Reconstruction of image <NUM> can be performed, for example, by image processor <NUM>.

<FIG> is a cross-sectional view of a tapered nose cone of a munition having an optically-neutral lens or dome that is conformal with the munition nose cone. In <FIG>, terminal-imaging seeker <NUM> depicted in <FIG> is reproduced, but instead of blunt window faceplate <NUM>, includes optically-neutral lens <NUM>. Optically-neutral lens <NUM> has front convex surface <NUM> which has a convex geometry that is conformal with nose cone <NUM>. Optically-neutral lens <NUM> has a front convex surface <NUM> configured to provide a high ballistic coefficient. Optically-neutral lens <NUM> is configured to transmit light received by front convex surface <NUM> to rear planar surface <NUM>, in an optically-neutral fashion.

Optical neutrality, as used in this context, means that images formed with and without optically-neutral lens by the imaging system, which includes spatial light modulator <NUM>, and focal plane array <NUM>, are substantially the same one to another. Such a condition results from an optically-neutral lens having no optical power. In the depicted embodiment, optical-neutrality can be obtained using a graded index (GRIN) material in optically-neutral lens. The refractive index of optically-neutral lens <NUM> is graded so as to transmit light from front convex surface <NUM> to rear planar surface <NUM> in an optically-neutral fashion (e.g., the transmitted light has the same phase and/or intensity relation at rear planar surface <NUM> with or without optically-neutral lens <NUM> in use). In various embodiments, various configurations of optically neutral lenses can be used. For example, the rear surface can be convex, concave or planar.

<FIG> is a cross-sectional view of a tapered nose cone of a munition having a tapered imaging fiber optic faceplate that is conformal with the munition nose cone. Using such a fiber optic faceplate, the alignment of the spatial light modulator and focal plane array need not be axial with the munition. The fiber optics can be configured to direct the received light to the spatial light modulator and focal plane array, however they are aligned with the tapered nose cone. In <FIG>, terminal-imaging seeker <NUM> depicted in <FIG> is reproduced, but instead of graded index lens <NUM>, includes tapered-imaging fiber-optic lens <NUM>'. Tapered-imaging fiber-optic lens <NUM>' again has front convex surface <NUM> which has a convex geometry that is conformal with nose cone <NUM>. And again, tapered-imaging fiber-optic lens <NUM>' has a front convex surface <NUM> configured to provide a high ballistic coefficient. Tapered-imaging fiber-optic lens <NUM>' is configured to transmit light received by front convex surface <NUM> to rear planar surface <NUM>, in an optically-neutral fashion (e.g., by maintaining a spatial intensity relation at the two surfaces <NUM> and <NUM>).

In another embodiment, a munition can be fitted with a standard glass lens. The standard glass lens can have an ogive shape on a leading surface and a flat rear planar surface. The standard glass lens need not be optically neutral. To correct for non-optical-neutrality, a planar metasurface lens may be affixed between the flat rear planar surface of the standard glass lens and focal plane array <NUM>.

<FIG> is block diagram of an embodiment of a terminal-imaging seeker and munition guidance and control system. In <FIG>, terminal-imaging seeker <NUM> includes controller <NUM>, spatial light modulator <NUM>, and optically-neutral lens <NUM>, Terminal-imaging seeker <NUM> is depicted interfacing with munition guidance and control system <NUM> of a munition. Controller <NUM> includes processor(s) <NUM>, input/output interface <NUM>, storage device(s) <NUM>, input devices <NUM>, output devices <NUM>, and focal plane array <NUM>. Storage device(s) <NUM> has various storage or memory locations. Storage device(s) <NUM> includes program memory <NUM>, and data memory <NUM>. Controller <NUM> is in communication with munition guidance and control system <NUM> via input/output interface <NUM>. Munition guidance and control system <NUM> can provide controller <NUM> with metrics indicative of a munition location, orientation, speed, etc. Controller <NUM> can provide munition guidance and control system <NUM> with signals indicative of location of a target relative to the munition, for example.

As illustrated in <FIG>, controller <NUM> includes processor(s) <NUM>, input/output interface <NUM>, storage device(s) <NUM>, input devices <NUM>, and output devices <NUM>. However, in certain examples, controller <NUM> can include more or fewer components. For instance, in examples where controller <NUM> is an image processing system, controller <NUM> may not include input devices <NUM> and/or output devices <NUM>. Controller <NUM> may include additional components such as a battery that provides power to components of controller <NUM> during operation, or additional sensors, etc. Controller <NUM> is shown in electrical communication with both focal plane array <NUM> and spatial light modulator <NUM>. Controller <NUM> can be configured to generate a control signal that causes spatial light modulator <NUM> to generate a coded aperture mask pattern. Controller <NUM> can be configured to receive, from focal plane array <NUM>, a signal indicative of an image of the scene as imaged through the coded aperture mask pattern generated in response to the control signal. Controller <NUM> can be configured to correct the image of the scene based on the signal received from focal plane array <NUM> and the specific coded aperture mask pattern corresponding to the signal received from focal plane array <NUM>.

Processor(s) <NUM>, in one example, is configured to implement functionality and/or process instructions for execution within controller <NUM>. For instance, processor(s) <NUM> can be capable of processing instructions stored in storage device(s) <NUM>. Examples of processor(s) <NUM> can include any one or more of a microprocessor, a controller, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other equivalent discrete or integrated logic circuitry.

Input/output interface <NUM>, in some examples, includes a communications module. Input/output interface <NUM>, in one example, utilizes the communications module to communicate with external devices via one or more networks, such as one or more wireless or wired networks or both. The communications module can be a network interface card, such as an Ethernet card, an optical transceiver, a radio frequency transceiver, or any other type of device that can send and receive information. The communications module can be a network interface card, such as an Ethernet card, an optical transceiver, a radio frequency transceiver, or any other type of device that can send and receive information. Other examples of such network interfaces can include Bluetooth, <NUM>, <NUM>, and Wi-Fi radio computing devices as well as Universal Serial Bus (USB). In some embodiments, communication with the munition or with an external aircraft, ship, base, etc. can be performed via a communications bus, such as, for example, an Aeronautical Radio, Incorporated (ARINC) standard communications protocol. In an exemplary embodiment, aircraft communication with the aircraft can be performed via a communications bus, such as, for example, a Controller Area Network (CAN) bus.

Storage device(s) <NUM> can be configured to store information within controller <NUM> during operation. Storage device(s) <NUM>, in some examples, is described as computer-readable storage media. In some examples, a computer-readable storage medium can include a non-transitory medium. The term "non-transitory" can indicate that the storage medium is not embodied in a carrier wave or a propagated signal. In certain examples, a non-transitory storage medium can store data that can, over time, change (e.g., in RAM or cache). In some examples, storage device(s) <NUM> is a temporary memory, meaning that a primary purpose of Storage device(s) <NUM> is not long-term storage. Storage device(s) <NUM>, in some examples, is described as volatile memory, meaning that storage device(s) <NUM> do not maintain stored contents when power to controller <NUM> is turned off. Examples of volatile memories can include random access memories (RAM), dynamic random access memories (DRAM), static random access memories (SRAM), and other forms of volatile memories. In some examples, storage device(s) <NUM> is used to store program instructions for execution by processor(s) <NUM>. Storage device(s) <NUM>, in one example, is used by software or applications running on controller <NUM> (e.g., a software program implementing long-range cloud conditions detection) to temporarily store information during program execution.

Storage device(s) <NUM>, in some examples, also include one or more computer-readable storage media. Storage device(s) <NUM> can be configured to store larger amounts of information than volatile memory. Storage device(s) <NUM> can further be configured for long-term storage of information. In some examples, Storage device(s) <NUM> include non-volatile storage elements. Examples of such non-volatile storage elements can include magnetic hard discs, optical discs, flash memories, or forms of electrically programmable memories (EPROM) or electrically erasable and programmable (EEPROM) memories.

Although terminal-imaging seekers <NUM> are typically embedded systems, in some embodiments, terminal-imaging seekers <NUM> can include input devices <NUM>. In some examples, input devices can be configured to receive input from a user, such as, for example, when in a configuration mode, and/or for calibration during manufacturing. Examples of input devices <NUM> can include a mouse, a keyboard, a microphone, a camera device, a presence-sensitive and/or touch-sensitive display, push buttons, arrow keys, or other type of device configured to receive input from a user. In some embodiments, input communication from the user can be performed via a communications bus, such as, for example, an Aeronautical Radio, Incorporated (ARINC) standard communications protocol. In an exemplary embodiment, user input communication from the user can be performed via a communications bus, such as, for example, a Controller Area Network (CAN) bus.

Although terminal-imaging seekers <NUM> are typically embedded systems, in some embodiments, terminal-imaging seekers <NUM> can include output devices <NUM>. Output devices can be configured to provide output to a user, such as, for example, during a configuration, and/or for calibration. Examples of output devices <NUM> can include a display device, a sound card, a video graphics card, a speaker, a cathode ray tube (CRT) monitor, a liquid crystal display (LCD), a light emitting diode (LED) display, an organic light emitting diode (OLED) display, or other type of device for outputting information in a form understandable to users or machines. In some embodiments, output communication to the user can be performed via a communications bus, such as, for example, an Aeronautical Radio, Incorporated (ARINC) standard communications protocol. In an exemplary embodiment, output communication to the user can be performed via a communications bus, such as, for example, a Controller Area Network (CAN) bus.

<FIG> is a diagram showing an embodiment according to the claimed subject-matter, of a spatial light modulator configured for use in a terminal-imaging seeker. In <FIG>, spatial light modulator <NUM>' is a spatial light modulator. Spatial light modulator <NUM>' includes transparent substrate <NUM>, first layer <NUM> of liquid-crystal elements, transparent interior layer <NUM>, second layer <NUM> of liquid-crystal elements, and transparent cover <NUM>. First layer <NUM> has liquid-crystal elements 82a, 82b, 82c, and 82d arranged in lines parallel to first transverse axis <NUM> and perpendicular to optical axis <NUM>. Second layer <NUM> has liquid-crystal elements 86a, 86b, 86c, and 86d arranged in lines parallel to second transvers axis <NUM> and perpendicular to both optical axis <NUM> and first transverse axis <NUM>. Such a linearly-patterned spatial light modulator <NUM>' as depicted in <FIG> would limit the coded aperture mask patterns to those that can be separated into perpendicular one-dimensional arrays of linear patterns.

Spatial light modulator <NUM>' can be created by utilizing reflective or absorptive liquid crystals placed in one-dimensional arrays across a transparent surface. One option for a thin application with minimal geometric blur could be to apply the liquid crystal to both sides of a single thin transparent substrate rather than on each of two separate substrates.

Also depicted in <FIG> is focal plane array <NUM>. In some embodiments, spatial light modulator <NUM>' can be manufactured directly upon focal plane array <NUM> so as to form a unitary device. In some embodiments Spatial light modulator <NUM>' and focal plane array <NUM> can be separate devices. For example, temperatures associated with manufacturing processes or installation requirements can drive design of spatial light modulator <NUM>' to be a separate part from the focal plane array <NUM>. In some embodiments, spatial light modulator <NUM>' could be installed onto focal plane array <NUM> using an optical adhesive.

<FIG> is a diagram showing an embodiment not according to the claimed subject-matter, of a spatial light modulator configured for use in a terminal-imaging seeker. In <FIG>, spatial light modulator <NUM>" is a spatial light modulator. Spatial light modulator <NUM>" includes a two-dimensional array of pixels 32xy. The two-dimensional array can include liquid-crystal and/or mirror pixels 32xy. The two-dimensional array is perpendicular the optical axis and aligned with the rows and columns of pixels of the focal plane array. Pixels 32xy can have boundaries that are less than a minimum mask feature size (e.g., less than a half wavelength of light) so that the separations between pixels are not seen in the image on the sensor. Such a two-dimensional pixel array, as depicted in <FIG>, can provide for more coded-aperture mask patterns than can be provided by perpendicular linear arrays, such as those depicted in the <FIG> embodiment. Liquid crystal and/or mirror materials can be designed for a specific energy or light wavelength sensed by the focal plane array. Coded aperture patterns can also be selected for specific wavelength optimization. Application of liquid crystals and/or mirrors can utilize vapor deposition, thin film methods or printing with liquid crystal inks.

Substrates and covers (e.g., transparent substrate <NUM> and transparent cover <NUM> depicted in <FIG>) can be made of a variety of materials and thicknesses and produced by several manufacturing methods. Glasses, plastics, and transparent ceramics can be utilized in the construction of the substrates. Substrates and/or covers can be made out of a coating material deposited in various fashions. Traditional material processing and manufacturing techniques can be employed for these materials, but more exotic methods, like vapor deposition and 3D printing, can also be used for manufacture. Substrate thickness and material can be tailored to provide mechanical robustness. Plastics may provide more flexibility in the design and lighter weight, where ceramics may be used in higher temperature applications.

Support circuitry for spatial light modulator <NUM>' and <NUM>" can be either placed outside of the region where energy must pass therethrough so as to reach focal plane array <NUM> or such support circuitry can be made of materials that are transparent to the wavelength sensed by focal plane array <NUM>. Such materials can include Indium Tin Oxide, for example.

Using spatial light modulator <NUM>' and/or <NUM>" instead of a static coded-aperture mask can permit programming of any desired coded pattern. A particular coded pattern might be well suited for a particular mission, CONOPS, or scene, a specific light intensity level, for example. A particular coded pattern might work well for a specific target or background within the scene. Spatial light modulator <NUM>' and/or <NUM>" can be programmed to generate well-suited coded patterns or to generate multiple patterns during a mission. In some scenarios, the coded patterns can change as a guided missile approaches its target, for example. Use of multiple coded patterns can permit exposures of the same scene using different coded-aperture masks so as to: i) reduce blur and other aberrations; ii) control light exposure of the scene; and/or iii) tune resolution of the corrected image of the scene.

Multiple exposures of the scene can be performed using the same coded pattern rotated at <NUM> degree increments or using completely different patterns, for example. The multiple images can be compared and combined into a single image for improved image reconstruction. An additional use of programming a particular pattern is that the SLM could be utilized to create a downsized physical window of the area of interest on the focal plane array. Perhaps to be used to aid in compressive sense.

Claim 1:
A system for creating a corrected image of a scene for a terminal-imaging seeker (<NUM>), the system comprising:
a lens (<NUM>) configured to receive light from a scene aligned with an optical axis;
a focal plane array (<NUM>) aligned with the optical axis and having an imaging region comprising a plurality of light-sensitive pixels;
a spatial light modulator (<NUM>) capable of generating a plurality of different coded-aperture mask patterns, each having a plurality of pinhole-like transparent apertures (<NUM>), the spatial light modulator comprising a plurality of electrically-controllable elements, each configured to modulate light transmission therethrough in response to an electrical control signal, the spatial light modulator aligned along the optical axis so as to transmit light through the plurality of pinhole-like transparent apertures onto the imaging region of the focal plane array thereby forming a raw super-imposed image of a corresponding plurality of overlapping images of the scene, wherein the spatial light modulator comprises two layers (<NUM>,<NUM>) of liquid-crystal elements, the first layer configured to controllably modulate light transmission in parallel lines perpendicular to the optical axis, the second layer configured to controllably modulate light transmission in parallel lines perpendicular to both the optical axis and the parallel lines of the first layer;
a controller (<NUM>) configured to generate an electrical control signal that causes the spatial light modulator to generate a first of the plurality of coded-aperture mask patterns; and
an image processor (<NUM>) configured to create, based on algorithms corresponding to the first of the plurality of coded-aperture mask patterns and on a first raw super-imposed image, the corrected image of the scene.