Abstract: Infrared imaging systems and methods incorporating the use of pixelated filter arrays integrated with the imaging detector. In one example, an infrared imaging system includes imaging optics that focus infrared radiation towards a focal plane of the system, an uncooled focal plane array sensor configured to receive the infrared radiation from the imaging optics, and a processor coupled to the uncooled focal plane array sensor and configured to receive and process image data received from the uncooled focal plane array sensor. The uncooled focal plane array sensor includes a two-dimensional array of microbolometer pixels and a corresponding two-dimensional filter array integrated and aligned with the two-dimensional array of microbolometer pixels such that each microbolometer pixel has a corresponding filter. The filter array is configured to filter the infrared radiation into at least two spectral bands or at least two polarizations.

Abstract: Device and method for optically switching a plurality of optical input signals include: receiving the plurality of optical input signals, wherein one or more of the optical input signals represent multiple channels at different channel frequencies; collimating the received plurality of optical input signals; removing noise between the channels by a comb filter; dispersing the collimated optical signals so that signals of different wavelength are separated by different angles; focusing the optical signals separated by different angles on a light switch device having a plurality of micromirrors; and controlling the light switch by a control signal to direct one or more of the optical signals separated by different angles to one or more output fibers for multicasting of the optical input signals.

Abstract: A free space line of site communication system for communicating between a first destination and a second destination includes a constellation of airborne platforms in a train-like formation, each travelling at a constant speed and distance relative to each other. Each of the airborne platforms includes: one or more inter-airborne platform optical or RF transceivers for communication with a previous and a next neighboring airborne platforms, wherein each inter-airborne platform transceiver is capable of adjusting its velocity to keep a constant speed and distance relative to its neighboring airborne platforms, and one or more up/down link transceivers for communication with multiple ground sites, each ground site having two or more ground optical or RF transceivers. A first airborne platforms closest to the first destination communicates with the first destination and a second airborne platforms closest to the second destination communicates with the second destination.

Abstract: A free space line of site communication system for communicating between a first destination and a second destination includes a constellation of airborne platforms in a train-like formation, each travelling at a constant speed and distance relative to each other. Each of the airborne platforms includes: one or more inter-airborne platform optical or RF transceivers for communication with a previous and a next neighboring airborne platforms, wherein each inter-airborne platform transceiver is capable of adjusting its velocity to keep a constant speed and distance relative to its neighboring airborne platforms, and one or more up/down link transceivers for communication with multiple ground sites, each ground site having two or more ground optical or RF transceivers. A first airborne platforms closest to the first destination communicates with the first destination and a second airborne platforms closest to the second destination communicates with the second destination.

Abstract: A free space optical communication system (100) and method including a constellation of several satellites (102). Each of satellites including: several inter-satellite optical telescopes (204) for optical communication with multiple neighboring satellites, each inter-satellite optical telescope is capable of adjusting its elevation angle to accommodate changes in the number of satellites in the constellation; and several up/down link optical telescopes (206) for optical communication with multiple ground sites, where each ground site has several ground optical telescopes. As the constellation passes a given ground site, some of the up/down-link telescopes of a given satellite are configured to track at least two respective ground optical telescopes of the given ground site and send data to the ground optical telescope with the clearest line of sight to the given satellite.

Abstract: A method and a system for vicarious characterization of a remote sensing sensor are described. The system includes a plurality of reflective mirrors configured and arranged to reflect radiation from a source of radiation onto a remotely located radiation sensor. The plurality of mirrors are spaced apart so as to obtain a plurality of distinct spot images on the remotely located radiation sensor. The system further includes a processor configured to analyze the plurality of spot images by fitting the images to obtain a point spread function of the remote sensing sensor.

Abstract: Described are computer-based methods and apparatuses, including computer program products, for determining a position. In some examples, the method includes determining measured time receipt differences from associated local receipt times for each pair of plurality of signals; determining a range difference for each of the plurality of signals based on the measured time receipt differences for each of the pairs of the plurality of signals; determining hypothesized range differences based on a hypothesized user position; determining an estimation difference for each of the plurality of signals based on the range difference and the hypothesized range difference for each of the plurality of signals based on a figure of merit; minimizing the estimation difference for the figure of merit based on a plurality of hypothesized user positions and an optimization routine; and outputting a user position based on a hypothesized user position associated with the minimized figure of merit.

Abstract: A system for determining properties of a radiant energy beam. The system include a plurality of fiber optic cables each including a first end and a second end and a plurality of optical coupling nodes coupled to a target body, wherein each optical coupling node includes one or more terminations, wherein each termination is coupled to the first end of one of the plurality of fiber optical cables to receive radiant energy from an incident radiant energy beam to determine properties of the radiant energy beam.

Abstract: One embodiment disclosed is a spectrometry system for collecting spatially and temporally co-registered hyperspectral data covering multiple spectral bands. The spectrometry system includes a single entrance slit for receiving light and a plurality of disperser elements operating over a plurality of distinct spectral bands to disperse the received light into constituent spectral channels. The system also includes a plurality of collimating and imaging optic elements that receive and re-image the dispersed light. The system also includes at least two focal plane arrays affixed in a common plane and configured to receive the re-imaged dispersed light, each of the at least two focal plane arrays being dedicated to sensing a distinct spectral band of the dispersed light.

Abstract: A methodology for initial orbit determination of an object about an astronomical body searches a grid of possible boundary values on the range-to-object over the observation interval to find the grid point and corresponding initial orbit that best fits all of the three or more (N) angles-only observations according to an error metric. The search is conducted by solving a boundary-value problem (e.g. Lambert's Problem) for different grid points. The state vector is propagated to determine estimated observation directions for the remaining N?2 observations. The grid point (and initial orbit) that best fit all of the observations is selected. The grid may be searched by testing each and every point on the grid or by using other optimization techniques such as hill climbing algorithms to find the optimal grid point. For efficiency, the search may start with a broad but coarse initial grid and increase the resolution of the grid as the search converges to a solution.

Abstract: A free space optical communication system (100) and method including a constellation of several satellites (102). Each of satellites including: several inter-satellite optical telescopes (204) for optical communication with multiple neighboring satellites, each inter-satellite optical telescope is capable of adjusting its elevation angle to accommodate changes in the number of satellites in the constellation; and several up/down link optical telescopes (206) for optical communication with multiple ground sites, where each ground site has several ground optical telescopes. As the constellation passes a given ground site, some of the up/down-link telescopes of a given satellite are configured to track at least two respective ground optical telescopes of the given ground site and send data to the ground optical telescope with the clearest line of sight to the given satellite.

Abstract: Described are methods and systems for vicarious polarimetric calibration and performance validation of a remote sensor. The system includes a plurality of reflective mirrors configured and arranged to reflect radiation from a source of radiation onto the remote sensor with accurately known polarimetric properties. Each of the reflective mirrors are located so that the target images do not overlap. The remote sensor is configured to receive the radiation reflected from the plurality of reflective mirrors and store the received radiation as image data (e.g., the image of each mirror appears as a point target). The system includes a processor configured to process the received data to provide direct calibration and performance validation for each polarimetric or spectral channel of the remote sensor. In addition, the calibration method removes all atmospheric effects except for transmittance and provides reference targets that have high polarimetric contrast, full spectrum performance and easy to deploy.

Abstract: Described are methods and systems for vicarious polarimetric calibration and performance validation of a remote sensor. The system includes a plurality of reflective mirrors configured and arranged to reflect radiation from a source of radiation onto the remote sensor with accurately known polarimetric properties. Each of the reflective mirrors are located so that the target images do not overlap. The remote sensor is configured to receive the radiation reflected from the plurality of reflective mirrors and store the received radiation as image data (e.g., the image of each mirror appears as a point target). The system includes a processor configured to process the received data to provide direct calibration and performance validation for each polarimetric or spectral channel of the remote sensor. In addition, the calibration method removes all atmospheric effects except for transmittance and provides reference targets that have high polarimetric contrast, full spectrum performance and easy to deploy.

Abstract: A free space optical communication system (100) and method including a constellation of several satellites (102). Each of satellites including: several inter-satellite optical telescopes (204) for optical communication with multiple neighboring satellites, each inter-satellite optical telescope is capable of adjusting its elevation angle; and several up/down link optical telescopes (206) for optical communication with multiple ground sites. As the constellation passes a given ground site, some of the up/down-link telescopes of a given satellite are configured to track at least two respective ground optical telescopes of the given ground site and send data to the ground optical telescope with the clearest line of sight to the given satellite. Moreover, each of the satellites includes optical circuitry (208, 210, 212, 216) for optically processing and switching incoming and outgoing optical signals without converting the optical signals into electrical signals.

Abstract: Various embodiments provide a satellite communication system including a first transceiver and a second transceiver geographically fixed on the earth, and a first satellite configured to communicate with the first transceiver through a first link. The system further includes a second satellite configured to communicate with the second transceiver through a second link and communicate with the first satellite through a laser communication crosslink. The first satellite and the second satellite are at a low earth orbit or medium earth orbit below the geostationary earth orbit of approximately 36000 km.

Abstract: One embodiment disclosed is a spectrometry system for collecting spatially and temporally co-registered hyperspectral data covering multiple spectral bands. The spectrometry system includes a single entrance slit for receiving light and a plurality of disperser elements operating over a plurality of distinct spectral bands to disperse the received light into constituent spectral channels. The system also includes a plurality of collimating and imaging optic elements that receive and re-image the dispersed light. The system also includes at least two focal plane arrays affixed in a common plane and configured to receive the re-imaged dispersed light, each of the at least two focal plane arrays being dedicated to sensing a distinct spectral band of the dispersed light.

Abstract: Geometric calibration of an imaging system is performed by recording visible control points in a calibration image whose geometric properties are known and calibration coefficients can be derived utilizing an image processing system for transforming the recorded image into a geometric distortion-free image. Described are methods and systems for vicarious geometric calibration of a remote sensor that include a processor configured to receive image data collected at a remote sensor, the image data including a plurality of image elements each associated with a respective reflective mirror from a plurality of reflective mirrors located at respective know positions, determine, for each of the plurality of reflective mirrors, an image location in the image data and determine one or more figures of merit based on the image locations and the known positions for each of the plurality of reflective mirrors.

Abstract: Described are methods and systems for vicarious polarimetric calibration and performance validation of a remote sensor. The system includes a plurality of reflective mirrors configured and arranged to reflect radiation from a source of radiation onto the remote sensor with accurately known polarimetric properties. Each of the reflective mirrors are located so that the target images do not overlap. The remote sensor is configured to receive the radiation reflected from the plurality of reflective mirrors and store the received radiation as image data (e.g., the image of each mirror appears as a point target). The system includes a processor configured to process the received data to provide direct calibration and performance validation for each polarimetric or spectral channel of the remote sensor. In addition, the calibration method removes all atmospheric effects except for transmittance and provides reference targets that have high polarimetric contrast, full spectrum performance and easy to deploy.

Abstract: A vibration control system includes a mechanical system which generates vibration; a sensor configured to measure the vibration and generate a vibration signal thereof, and a processor configured: (a) receive a vibration signal from a sensor in a mechanical system; (b) model the vibration signal using a time-domain function; (c) adjust one of an amplitude coefficient and a phase coefficient of the modeled vibration signal; (d) output a control signal corresponding to the modeled vibration signal to the mechanical system so as to reduce the vibration; and (e) receive another vibration signal from the sensor. Steps (c)-(e) are repeated when the average value of the vibration signal is greater than a predetermined value. A method for vibration control is also disclosed.

Abstract: A free space optical communication system (100) and method including a constellation of several satellites (102). Each of satellites including: several inter-satellite optical telescopes (204) for optical communication with multiple neighboring satellites, each inter-satellite optical telescope is capable of adjusting its elevation angle; and several up/down link optical telescopes (206) for optical communication with multiple ground sites. As the constellation passes a given ground site, some of the up/down-link telescopes of a given satellite are configured to track at least two respective ground optical telescopes of the given ground site and send data to the ground optical telescope with the clearest line of sight to the given satellite. Moreover, each of the satellites includes optical circuitry (208, 210, 212, 216) for optically processing and switching incoming and outgoing optical signals without converting the optical signals into electrical signals.