Abstract: A configurable sunshade for use with a multiple-camera system that has multiple camera sensors with associated fields of view. The sunshade has multiple portions that are independently rotatable with respect to a fixed platform such that in distinct orientations with respect to each other, specified cameras may be blocked from receiving light from a scene, in whole or in part. In other embodiments, individual apertures of a multi-sunshade housing may be separately activated.

Abstract: A nanophotonic phased array is configured to generate dynamic three-dimensional imagery when employed as an oscillatory beam-steering device. A scanning nanophotonic phased array generates programmable light fields. That is, a phased array generates reconfigurable light fields when controlled to perform an angular scan of incident illumination synchronized with respect to modulation of the incident illumination.

Abstract: A steerable optical transmit and receive terminal includes a MEMS-based N×1 optical switch network. Each optical switch in the optical switch network uses an electrostatic MEMS structure to selectively position a translatable optical grating close to or far from an optical waveguide. In the close (“ON”) position, light couples between the translatable optical grating and the optical waveguide, whereas in the far (“OFF”) position, no appreciable light couples between the translatable optical grating and the optical waveguide. The translatable optical grating is disposed at or near a surface of the optical switch network. Thus, the translatable optical grating emits light into, or receives light from, free space. The steerable optical transmit and receive terminal also includes a lens and can steer a free space optical beam in a direction determined by which port of the N×1 optical switch network is ON.

Abstract: An all-solid state optical transmit/receive terminal includes binary optical switches to steer an optical beam, without mechanical components, phased array of emitters/collectors or large number of phase shifters. A lens optically couples a surface array of emitters/collectors to free space, giving each emitter/collector a respective direction in free space. The emitters/collectors are also coupled, via an “H-tree” or other branched optical waveguide network, to a common input/output port, and from there to a receiver and/or transmitter. The binary optical switches are disposed at optical junctions of the optical waveguide network. ON switches pass an optical signal through the optical waveguide network, between the common input/output port and one or more selected emitter/collectors, thereby selecting a free space direction(s). Only a relatively small subset of the binary optical switches needs to be ON, therefore powered, simultaneously at any given time.

Abstract: A visual navigation system includes a compass configured to orient a user in a heading direction, an image sensor configured to capture a series of successive navigation images in the heading direction, one or more of the navigation images having at least two reference markers, data storage memory configured to store the series of successive navigation images, a navigation processor configured to identify at least one principal marker and at least one ancillary marker from the at least two reference markers, the principal marker positioned within a principal angle and the ancillary marker positioned within an ancillary angle, which is greater than the principal angle, and to determine heading direction information based on a position of the at least one principal marker and/or the at least one ancillary marker in the successive navigation images, and a user interface configured to provide the heading direction information to the user.

Abstract: A multi-beam optical phased array on a single planar waveguide layer or a small number of planar waveguide layers enables building an optical sensor that performs much like a significantly larger telescope. Imaging systems use planar waveguides created using micro-lithographic techniques. These imagers are variants of “phased arrays,” common and familiar from microwave radar applications. However, there are significant differences when these same concepts are applied to visible and infrared light.

Abstract: A star tracker determines a location or orientation of an object, such as a space vehicle, by observing unpolarized light from one or more stars or other relatively bright navigational marks, without imaging optics, pixelated imaging sensors or associated pixel readout electronics. An angle of incidence of the light is determined by comparing signals from two or more differently polarized optical sensors. The star tracker may be fabricated on a thin substrate. Some embodiments have vertical profiles of essentially just their optical sensors. Some embodiments include micro-baffles to limit field of view of the optical sensors.

Abstract: Methods and apparatus automatically determine a location, such as of an aircraft or spacecraft, by matching images of terrain below the craft, as captured by a camera, radar, etc. in the craft, with known or predicted terrain landmark data stored in an electronic data store. A star tracker measures attitude of the camera. Optionally, a rangefinder measures altitude of the camera above the terrain. A navigation filter uses the attitude, and optionally the altitude, to resolve attitude, and optionally altitude, ambiguities and thereby avoid location solution errors common in prior art terrain matching navigation systems.

Abstract: A navigation system determines a position by referring to artificial or natural satellites or other space objects during daylight or when the objects are in a planet's shadow. A telescope and image sensor observe and image shadows of the objects as the objects transit the sun or a sunlit surface of a planet or moon, thereby solving problems related to the two key times during which traditional SkyMark navigation is difficult or impossible.

Abstract: A star camera system that includes an optical system configured to focus radiation from a star to be imaged onto a collector. Specifically, the collector is in the form of an electron bombarded active pixel sensor (EBAPS) configured to provide high gain. The EBAPS comprising a photocathode disposed in a vacuum is configured to release electron into a vacuum when exposed to radiation focused thereon by the optical system. In addition, the EBAPS includes an active pixel sensor anode disposed distant from the photocathode in the vacuum. An electric field is generated by a voltage source to direct electrons from the photocathode to the active pixel sensor anode to thereby generate an image of the star.

Abstract: Methods and computer products for establishing at least one of attitude, direction and position of a moving platform. At least one skymark of known ephemeris is imaged at each of a first set of discrete instants by means of an optical sensor coupled to the platform. A measurement is also obtained of the attitude of the platform at each of a second set of discrete instants by means of an inertial navigation system. A recursive of estimation filter is then applied to successive skymark position vectors to update an estimate of platform navigation state, with the measurement of attitude of the platform tightly coupled to the estimate of platform navigation state as updated by the recursive estimation filter. Various techniques of frame stacking and multi-hypothesis tracking may be applied to improve the robustness of navigation solutions.

Abstract: Scattered light in the sky (sky glow) from light sources at one or more known geographic locations is used as reference point(s), from which geographic location of a system observing the sky glow is automatically ascertained. The light is scattered by particulates in the atmosphere. An upward looking camera captures an image of the sky, including the sky glow. A search engine automatically searches a catalog of modeled or pre-stored sky glows for a model that matches the image. Each model is associated with a geographic location. The models characterize each sky glow, such as in terms of color, intensity, etc., as the sky glow would appear from the associated geographic location. If a matching model is found, within a predetermined match criterion, the system outputs the geographic location associated with the matching model. Optionally, the geographic location is used to select and display a map of the geographic location.

Abstract: Methods and apparatus ascertain a geographic position based on topographic contours of ocean surfaces. Observed ocean topographic contours are matched to predicted ocean topography and/or ocean topographic information stored in a database. Such systems and methods do not necessarily require INS, GPS, RF beacons, optical beacons or celestial sightings. These systems and methods may be used as references to correct INS. These systems and methods may be used to ascertain a geographic location of an aircraft, spacecraft, watercraft, landcraft (vehicle), person or the like. Similarly, these systems and methods may be used as part of a guidance system for guiding a craft to a destination. These systems and methods may be used in tandem with, or as backups for, other types of navigation or guidance systems or as one input to a navigation filter.

Abstract: A star camera system that includes an optical system configured to focus radiation from a star to be imaged onto a collector that is in the form of an electron bombarded active pixel sensor (EBAPS) configured to provide high gain. The EBAPS comprising a photocathode disposed in a vacuum is configured to release electrons into the vacuum when exposed to radiation focused thereon by the optical system. The EBAPS includes an active pixel sensor anode disposed distant from the photocathode in the vacuum. An electric field is generated by a voltage source to direct the electrons from the photocathode to the active pixel sensor anode. Furthermore, the collector is mounted on a translation device configured to move the collector relative to the optical system by a predetermined amount of less than pixel size in the focal plane of the optical system to increase image resolution of a plurality of images.

Abstract: A digital camera optically couples a monocentric lens to image sensor arrays, without optical fibers, yet shields the image sensor arrays from stray light. In some digital cameras, baffles are disposed between an outer surface of a monocentric lens and each image sensor array to shield the image sensor arrays from stray light. In other such digital cameras, an opaque mask defines a set of apertures, one aperture per image sensor array, to limit the amount of stray light. Some digital cameras include both masks and baffles.

Abstract: A zero-optical-path-length-difference optical phased array built with essentially planar photonic devices determines a direction to an incoherent optical source, such as a star. The phased array can replace a 3-dimensional star tracker with a nearly 2-dimensional system that is smaller and lighter. The zero-optical-path-length-difference phased array can be optically connected to an interferometer. Driven by a light source, the zero-optical-path-length-difference phased array can be used as an optical projector.

Abstract: A star tracker determines a location or orientation of an object, such as a space vehicle, by observing unpolarized light from one or more stars or other relatively bright navigational marks, without imaging optics, pixelated imaging sensors or associated pixel readout electronics. An angle of incidence of the light is determined by comparing signals from two or more differently polarized optical sensors. The star tracker may be fabricated on a thin substrate. Some embodiments have vertical profiles of essentially just their optical sensors. Some embodiments include micro-baffles to limit field of view of the optical sensors.

Abstract: Methods and apparatus ascertain a geographic position based on topographic contours of ocean surfaces. Observed ocean topographic contours are matched to predicted ocean topography and/or ocean topographic information stored in a database. Such systems and methods do not necessarily require INS, GPS, RF beacons, optical beacons or celestial sightings. These systems and methods may be used as references to correct INS. These systems and methods may be used to ascertain a geographic location of an aircraft, spacecraft, watercraft, landcraft (vehicle), person or the like. Similarly, these systems and methods may be used as part of a guidance system for guiding a craft to a destination. These systems and methods may be used in tandem with, or as backups for, other types of navigation or guidance systems or as one input to a navigation filter.

Abstract: A pixel array including circuitry for combining charges accumulated by individual pixels in the array enables addition and/or subtraction of individual pixel values, prior to their digitization, in the pixel array.

Abstract: A star camera system that includes an optical system configured to focus radiation from a star to be imaged onto a collector that is in the form of an electron bombarded active pixel sensor (EBAPS) configured to provide high gain. The EBAPS comprising a photocathode disposed in a vacuum is configured to release electrons into the vacuum when exposed to radiation focused thereon by the optical system. The EBAPS includes an active pixel sensor anode disposed distant from the photocathode in the vacuum. An electric field is generated by a voltage source to direct the electrons from the photocathode to the active pixel sensor anode. Furthermore, the collector is mounted on a translation device configured to move the collector relative to the optical system by a predetermined amount of less than pixel size in the focal plane of the optical system to increase image resolution of a plurality of images.