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: 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 configurable optical baffling includes an outer housing positioned above a fixed platform and has an outer opening. An inner housing is layered below the outer housing and above the fixed platform and has inner openings and inner shaded sections. The outer opening includes an elongated sensing boresight having a longitudinal boresight axis and opposing ends. An outer boresight opening end is open to the light from the scene, and a reflecting end has a flat fold mirror that is configured to reflect light from the outer boresight opening in towards the inner housing so that the optical baffling is configured to receive light from the scene solely from a single look direction along the boresight axis, the single look direction being changeable by rotation of the outer housing.

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: A configurable optical baffling includes an outer housing positioned above a fixed platform and has an outer opening. An inner housing is layered below the outer housing and above the fixed platform and has inner openings and inner shaded sections. The outer opening includes an elongated sensing boresight having a longitudinal boresight axis and opposing ends. An outer boresight opening end is open to the light from the scene, and a reflecting end has a flat fold mirror that is configured to reflect light from the outer boresight opening in towards the inner housing so that the optical baffling is configured to receive light from the scene solely from a single look direction along the boresight axis, the single look direction being changeable by rotation of the outer housing.

Abstract: A steerable optical transmit and receive terminal includes a MEMS-based N×1 optical switching network. Each optical switch in the switching 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 switching 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 switching network is ON.

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 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 single photon detection circuit is described that includes a germanium photodiode that is configured with zero voltage bias to avoid dark current output when no photon input is present and also is configured to respond to a single photon input by generating a photovoltaic output voltage. A single electron bipolar avalanche transistor (SEBAT) has a base emitter junction connected in parallel with the germanium photodiode and is configured so that the photovoltaic output voltage triggers an avalanche collector current output.

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 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 tracker includes a lens slice, a pixelated image sensor, an ephemeral database and a processor configured to estimate attitude, orientation and/or location of the star tracker based on an image of one or more celestial objects projected by the lens slice onto the pixelated image sensor. The lens slice is smaller and lighter than an optically comparable conventional lens, thereby making the star tracker less voluminous and less massive than conventional star trackers. A lens slice is elongated along one axis. Optical performance along the elongation axis is comparable to that of a conventional circular lens of equal diameter. Although optical performance along a width axis, perpendicular to the elongation axis, of a lens slice can be significantly worse than that of a conventional lens, use of two orthogonal lens slices provides adequate optical performance in both axes, and still saves volume and mass over a conventional lens.

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: A steerable optical transmit and receive terminal includes a MEMS-based N×1 optical switching network. Each optical switch in the switching 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 switching 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 switching network is ON.

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. An additional navigation aiding sensor provides additional navigational data. Optionally, a rangefinder measures altitude of the camera above the terrain. A navigation filter uses the attitude, the additional navigational data, 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 distributed navigation system architecture includes a plurality of navigation platforms, each having a universal navigation processor configured to communicate with other universal navigation processors, one or more relative navigation systems configured to provide source information to the navigation platforms, an anchor navigation node disposed on one or more of the plurality of navigation platforms in order to form one or more anchor navigation platforms, the anchor navigation node, including an inertial navigation system, a clock, and one or more absolute navigation systems, configured to determine navigation information based on the inertial navigation system, the clock, the one or more absolute navigation systems and optionally the source information, the one or more anchor navigation platforms providing the navigation information to the other navigation platforms, and a navigation processor system in communication with each of the universal navigation processors in order to provide operating informat

Abstract: A geo-location system determines location histories for geo-locator devices in shipments. The devices generate and store environmental measurements, which are retrieved and compared to data from an environmental conditions database to calculate location histories. The measurements generated by sensors of the devices are encrypted along with hashed iterations, using one-way hash functions, of unique seed numbers associated with each device. The series of hashed iterations are compared to independently calculated series to determine if the devices have been tampered with. Location histories of devices included in common shipments are compared to determine whether devices have been tampered with. The location histories are compared to the expected routes of the shipments to determine if shipments were diverted. The atmospheric pressure measurements recorded by devices in shipments sealed under constant pressure are analyzed to determine if the shipments were unsealed.

Abstract: This invention discloses a multispectral imaging system, DFPA (digital focal plane array), in the form of an integrated circuit of three structures each of which is implemented on a chip. The top structure consists of detectors capable of imaging in the visible to LWIR wavelengths. The middle structure of neuromorphic focal array contains ROI circuitry and inherent computing capabilities for digitization, convolution, background suppression, thresholding, and centroid determination of the ROIs. The bottom structure (dubbed common digital layer) is capable of additional image processing tasks and reconfiguring the neuromorphic focal array. In a simpler embodiment of the invention, the system only has the top two layers, with an external processor taking over the role of the common digital layer.

Abstract: An image-based navigation system is arranged to obtain a terrain image of a target terrain from one or more image sensors at a low altitude imaging location. The terrain image includes at least one celestial image feature and at least one terrain feature. Map database information stored in at least one hardware memory device is accessed and compared to the at least one celestial image feature and the at least one terrain feature in the terrain image to determine absolute location coordinates of the imaging location.

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.