Abstract: An illustrative system obtains connectivity data for an optical wireless communication link between an optical wireless signal transmitter implemented on a first in-flight aerial vehicle and an optical wireless signal receiver implemented on a second in-flight aerial vehicle, determines, based on the connectivity data, a status of the optical wireless communication link, and performs, based on the status of the optical wireless communication link, a connectivity management operation configured to facilitate connectivity of the optical wireless signal receiver with the optical wireless signal transmitter by way of the optical wireless communication link. Corresponding methods and systems are also described.

Abstract: An underwater communications system is provided that transmits electromagnetic and/or magnetic signals to a remote receiver. The transmitter includes a data input. A digital data compressor compresses data to be transmitted. A modulator modulates compressed data onto a carrier signal. An electrically insulated, magnetic coupled antenna transmits the compressed, modulated signals. The receiver that has an electrically insulated, magnetic coupled antenna for receiving a compressed, modulated signal. A demodulator is provided for demodulating the signal to reveal compressed data. A de-compressor de-compresses the data. An appropriate human interface is provided to present transmitted data into text/audio/visible form. Similarly, the transmit system comprises appropriate audio/visual/text entry mechanisms.

Abstract: A software defined network including a constellation of software defined satellites. Each software defined satellite includes computing resources that are dynamically configurable to provide at least one of a plurality of different types of services. Each software defined satellite further includes an interface that interfaces with a software defined network ground station.

Abstract: Methods, devices, and systems are described for free space optical communication. An example device can comprise a laser, a modulator configured to cause the laser to output an optical signal comprising a data signal and a beacon signal, a defocuser optically coupled to the laser and configured to receive the optical signal and control a beam divergence of the optical signal, an optical interface configured to receive the optical signal from the defocuser and output the optical signal into free space, and a controller configured to cause the defocuser to adjust the beam divergence based on an operational mode of the laser.

Abstract: The present invention discloses a method of simultaneously acquiring vertical profiles of multiple atmospheric parameters. Measuring devices based on multiple principles and capable of measuring multiple parameters simultaneously are fixed on a cable of an aerostat at specified distance decided by measurement task, each measuring device finishes measuring the atmospheric parameters at its altitude thereof, and transmits data to a ground data acquisition and processing device in real time, so as to synchronously acquire the real-time measured profiles of multiple atmospheric parameters. The profile data does not have any assumption, and standard data can be provided to a ground remote sensing device like radar for measuring at the same place while regular meteorological parameters and atmospheric contamination data are provided to atmospheric and environmental governance departments.

Abstract: The present invention relates to a method and an apparatus for continuously detecting a hazardous and noxious substance from multiple satellites, and specifically, provides a method and an apparatus for continuously detecting a hazardous and noxious substance from multiple satellites, the method and apparatus: receiving a multi-satellite image which is photographed by a multi-satellite comprising a satellite having an imaging radar (SAR), a satellite having an infrared sensor, and a satellite having an electronic optical sensor; acquiring a reference image, of the satellite having the SAR, including a ground control point of an observed region; extracting a corresponding point between the reference image and the multi-satellite image; implementing the image matching and geometric correction for the multi-satellite image by using the extracted corresponding point; confirming at least one among the brightness value of pixels of the SAR satellite image, the temperature value of pixels of the infrared satellite i

Abstract: Broadband satellite communications systems using optical feeder links are disclosed. Various optical modulation schemes are disclosed that can provide improved capacity for fixed spot beam, on board beamforming, and ground-based beamforming broadband satellite systems.

Abstract: An emission/reception device is configured for communication between a ground station and a mobile craft which is provided with a retro-reflector configured to modulate a laser beam received along a direction and to return it along the direction, the mobile craft being situated above a backscattering zone, the emission/reception device generating at least two temporally offset emission/reception sequences, each being associated with a laser beam and comprising successive pairs of associated emission and reception phases, the emission phase including emitting a laser beam from the ground station towards the mobile craft, and the reception phase including receiving a laser beam returned by the retro-reflector, each reception phase being deactivated during the transit through the backscattering zone of the laser beam emitted during the associated emission phase.

Abstract: Broadband satellite communications systems using optical feeder links are disclosed. Various optical modulation schemes are disclosed that can provide improved capacity for fixed spot beam, on board beamforming, and ground-based beamforming broadband satellite systems.

Abstract: A communication system on a platform and a method of performing optical communication using an array lidar system comprising a plurality of illuminators on a platform include transmitting beams from a first set of the plurality of illuminators, receiving reflections resulting from the beams to perform target detection, and transmitting modulated optical signals from a second set of the plurality of illuminators. Receiving the modulated optical signals is done to perform the optical communication.

Abstract: An apparatus and method for tracking a laser communication signal of interest incident on a focal plane array (FPA) identifies a plurality of “hotspots” in a scene of interest, and aligns a hotspot that is a signal of interest (SOI) or beacon component thereof with the FPA. Hotspot centroids can be estimated within a fraction of an FPA pixel by considering squares of four pixels and comparing their signal amplitudes. A multi-spot calculation is used to improve the position estimates of all of the hotspots by applying a Kalman filter to the hotspot position data and assuming that the relative hotspots positions are fixed. The calculation is periodically repeated to enable tracking of the SOI. Amplitude variability of the hotspots is accommodated by weighting the hotspot contributions according to their intensities. In embodiments, estimation error of the SOI centroid is less than a smallest dimension of the FPA pixels.

Abstract: A laser communication apparatus is provided for sending and receiving messages. A processor encodes user messages for a modulator. The modulator provides control signals related to the encoded message to a plurality of seed lasers. Each seed laser can provide light at a different wavelength. Amplifiers are joined to amplify light from the seed lasers. Amplified light is multiplexed together. Multiplexed light is transmitted by a collimating lens along a target vector. A portion of the light can be monitored by a first detector. A telescope receives light from the target vector and provides focused light to a second detector. The second detector provides a signal responsive to the received light to the processor. The processor decodes this signal to provide the received message.

Abstract: A system includes a wireless network and a software defined network overlaid over the wireless network. The software defined network includes at least one UAV having a software defined network device and a bridging radio component. The system includes a communication component in communication with the bridging radio component and a controller connected to the software defined network that makes routing decisions and communicates the routing decisions to the software defined network device.

Abstract: An apparatus is described which uses directly modulated InGaN Light-Emitting Diodes (LEDs) or InGaN lasers as the transmitters for an underwater data-communication device. The receiver uses automatic gain control to facilitate performance of the apparatus over a wide-range of distances and water turbidities.

Abstract: In some embodiments, the present invention provides an apparatus and process that includes control electronics that generate an electronic control signal; and a plurality of optically or electrically pumped semiconductor lasers, quantum-cascade lasers, optical parametric generators, or optical parametric oscillators, operatively coupled to the control electronics, that output an optical signal having a plurality of wavelengths, each wavelength having an output intensity that each of which is varied over time to simulate a combustion signature of a weapon. In some embodiments, the optical signal includes at least two different infrared wavelengths that are varied differently with time.

Abstract: Optical communications system (10) and method for transmission of payload data (PD) from a low earth orbit satellite (20) to an optical ground terminal (30), the low earth orbit satellite (20) being connectable with the optical ground terminal (30) via an optical downlink channel (DL), and the optical ground terminal (30) being connectable with the low earth orbit satellite (20) via an uplink channel (UC); wherein said uplink channel (UC) is an acquisition and tracking beacon channel by means of a ground beacon (GB) controlled by a point-acquisition-track subsystem (PAT), the ground beacon (GB) comprising a wide angle beam (W) for acquisition and a guidance beam (G) for tracking; and wherein the ground beacon (GB) for the uplink channel (UC) is a pulse position modulated PPM channel.

Abstract: Optical downlink system (10) and method of optical data transmission between a remote terminal (20) having a number of n optical communication terminals (OT1-OTn), and a ground terminal (30) comprising a cluster of n optical ground stations (OGS1-OGSn) connected by n optical downlink channels (DL1-DLn) respectively n optical uplink channels (UC1-UCn) characterised by a spatial separation of the optical downlink channels (DL1-DLn) and a temporal separation of the optical uplink channels (UC1-UCn).

Abstract: A free space optical communication system (100) and method including: several optical beam expanders (414) for receiving incoming optical signals from ground sites and neighboring satellites; several optical preamplifiers (412) for preamplifying the received optical signals; one or more optical main amplifiers (404) for amplifying the preamplified optical signals; and an optical switch (408) for directing respective amplified optical signals to respective destinations via a respective optical beam expander. The respective amplified optical signals are inputted to a respective optical beam expander (414) for transmission to said respective destinations, as outgoing optical signals.

Abstract: A balloon envelope with an integrated receiver. In an example embodiment, a balloon includes: (i) an envelope including one or more signal passing sections, each of the one or more signal-passing sections being configured to allow a signal to pass through; (ii) at least one signal receiver corresponding to a particular one of the one or more signal passing sections; and (iii) at least one signal-directing surface located within the envelope and corresponding to the particular one of the one or more signal-passing sections, the at least one signal-directing surface being configured to receive the signal and direct the signal towards the at least one signal receiver.

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: A laser communications terminal configured for simultaneous two-way stabilized communications links to multiple ground sites. One example of such a laser communications terminal includes a plurality of laser channels, each including a channel transceiver configured to transmit and receive an optical signal, an afocal telescope optically coupled to each of the channel transceivers, a celostat minor pair optically coupled to the afocal telescope, and a plurality of beam steering mirrors, at least one beam steering mirror associated with each channel of the plurality of laser channels and configured to independently steer the corresponding optical signal within a field of view of the afocal telescope.

Abstract: A method and apparatus for providing link establishment in the access segment of the communications network using broadband multi-wavelength LED are disclosed. In one embodiment, such links may be established in point-to-point, point-to-multipoint, multipoint-to-multipoint, or ring format depending on the topology required for optimized access network build-out.

Abstract: Exemplary embodiments may involve hierarchical balloon networks that include both optical and radio frequency links between balloons. An exemplary network system may include: (a) a plurality of super-node balloons, where each super-node balloon comprises a free-space optical communication system for data communications with one or more other super-node balloons and (b) a plurality of sub-node balloons, where each of the sub-node balloons comprises a radio-frequency communication system that is operable for data communications. Further, at least one super-node balloon may further include an RF communication system that is operable to transmit data to at least one sub-node balloon, where the RF communication system of the at least one sub-node balloon is further operable to receive the data transmitted by the at least one super-node balloon and to transmit the received data to at least one ground-based station.

Abstract: A transmitter includes an optical data modulation unit which modulates an optical carrier having a first frequency with a data signal and outputs the optical carrier as a signal light, an optical frequency shift unit which shifts and outputs the frequency of the signal light from the first frequency to a second frequency based on a predetermined frequency offset amount, and a frequency offset control unit which controls the frequency offset amount such that a harmonic component generated in the optical frequency shift unit does not overlap with a band of the data signal.

Abstract: Certain embodiments of the invention may include systems, methods, and apparatus for improving the visibility and identification of satellites using light emitting diodes. According to an example embodiment of the invention, a method is provided for improving the visibility of satellites. The method can include attaching one or more light emitting diodes (LEDs) to a satellite, supplying one or more signals to the one or more LEDs, and producing light emission having a unique identifier from the one or more LEDs based at least in part on the one or more signals.

Abstract: An apparatus and method for implementing a flexible distributed antenna system (DAS) head end are disclosed. A flexible DAS head end includes an RF conditioning module configured to be connected to one or more base station transceiver (BTS) devices and one or more low-power RF modules that are also part of the flexible DAS head end. In an example embodiment, the flexible DAS head end receives high-power digital-RF passband transmissions from its connections to the one or more BTS devices, and low-power digital-RF passband signals from the one or more low-power RF modules. The low-power RF modules, in turn, can receive input baseband signals from one or more baseband units (BBUs) in a wireless network, and then convert the input signals to the lo low-power digital-RF passband signals. The RF conditioning module constructs one or more superposition RF signals from the passband signals, and routes and transmits them to an array of antenna nodes.

Abstract: An optical LNB capable of fast position-adjusting is employed in an LNBF. The optical LNB includes a down-converting device coupled to an OMT of the LNBF for down-converting a polarized signal for generating a first intermediate frequency signal, a branching device for branching the first intermediate frequency signal for generating a second and a third intermediate frequency signals, an electrical/optical converting device coupled to the branching device for converting the second intermediate frequency signal into an optical signal, and a power end for receiving power from a power supply and outputting the third intermediate frequency signal.

Abstract: Optical communications system (10) and method for transmission of payload data (PD) from a low earth orbit satellite (20) to an optical ground terminal (30), the low earth orbit satellite (20) being connectable with the optical ground terminal (30) via an optical downlink channel (DL), and the optical ground terminal (30) being connectable with the low earth orbit satellite (20) via an uplink channel (UC); wherein said uplink channel (UC) is an acquisition and tracking beacon channel by means of a ground beacon (GB) controlled by a point-acquisition-track subsystem (PAT), the ground beacon (GB) comprising a wide angle beam (W) for acquisition and a guidance beam (G) for tracking; and wherein the ground beacon (GB) for the uplink channel (UC) is a pulse position modulated PPM channel.

Abstract: A communication system for providing world-wide, mobile Internet communication to a plurality of users and a method therefore. The system includes ground-based, multi-channel, radio frequency transmitting and receiving broadcasting grids that are capable of providing content to multiple users via cell towers and low-altitude, optical transmitting and receiving satellites that are in optical communication with the ground-based, multi-channel, RF transmitting and receiving broadcasting grids. The method includes transmitting optical and/or RF signals between at least one of the ground-based, multi-channel, RF transmitting and receiving broadcasting grids and at least one of the low-altitude, optical transmitting and receiving satellites.

Abstract: A method and apparatus for providing link establishment in the access segment of the communications network using broadband multi-wavelength LED are disclosed. In one embodiment, such links may be established in point-to-point, point-to-multipoint, multipoint-to-multipoint, or ring format depending on the topology required for optimized access network build-out.

Abstract: An optical data transmission apparatus is provided, in which a first communication unit 101 and a second communication unit 102 arranged to freely move relatively to each other each include an optical signal transmission unit having a laser diode 120 for emitting single-mode light, a multi-mode optical fiber 111 for guiding a single-mode optical signal output from the laser diode 120 , converting the single-mode optical signal into a multi-mode optical signal, and outputting the multi-mode optical signal, an optical lens 112 for forming the optical signal output from the multi-mode optical fiber 111 into parallel light, and a first polarization element for passing the optical signal polarized in a predetermined direction out of optical signals output from the optical lens 112.

Abstract: A free-space optical communications network for allowing a plurality of geographically-distributed users to communicate may include free-space multi-channel relay converters for tracking a plurality of users, and a connection system in communication with each of the plurality of multi-channel relay converters. The connection system may include an internal alignment reference and steering mirrors. Each free-space multi-channel relay converter may be adapted to align with the internal alignment reference. The connection system may be adapted to align the plurality of free-space multi-channel relay converters with one another to allow the plurality of geographically-distributed users to communicate.

Abstract: A space-time division multiple-access (STDMA) laser communications (lasercom) system and related techniques. The STDMA system includes a plurality of remote nodes and an STDMA access node which uses precise electronic beam steering and beacons to provide access to each of a plurality of remote access nodes by means of both space and time-division multiple access.

Abstract: A free-space network may include: at least one free-space sensor for sensing at least one uncooperative target; at least one free-space communications network for allowing a plurality of cooperative users to communicate, at least one free-space processor for processing information from the at least one free-space sensor and information from the at least one free-space communications network; and at least one free-space communications link connecting in free-space the at least one free-space sensor, the at least one free-space communications network, and the at least one free-space processor. The at least one free-space communications network may include a plurality of free-space multi-channel relay converters for tracking a plurality of cooperative users, and a connection system for aligning the plurality of free-space multi-channel relay converters with one another to allow a plurality of cooperative users to communicate.

Abstract: The systems and methods described herein allow a user to communicate using a ground sensor network that is capable of both line-of-sight (LOS) and non-line-of-sight (NLOS) communication. In particular, the systems and methods herein described transmit and receive ultraviolet radiation having a wavelength within the solar blind region from a plurality of sensing nodes arranged both in a LOS network, which communicates via LOS communication, and in a NLOS network, which communicates via NLOS communication. The ultraviolet radiation is then transmitted from the plurality of sensing nodes to a remote receiver, via LOS communication.

Abstract: The present invention is directed toward systems for conducting laser range and enabling optical communication between a plurality of entities and to the application of such systems in a secure covert combat identification system. In one embodiment, the present invention uses a novel laser system that generates high pulse rates, as required for optical communications, while concurrently generating sufficiently high power levels, as required by laser range finding operations. One application of the present invention is in enabling secure covert communications between a plurality of parties. Another application of the present invention is in tracking and identifying the movement of objects.

Abstract: A satellite or spacecraft in low Earth orbit, when in eclipse and not illuminated by sunlight, represents a low-bandwidth datastream through modulation of a source of uncollimated light, such as a set of light emitting diodes. Transmission modes include generating patterns in the color, intensity or polarization of a light source, or precise timing control of a strobe signal. A ground station tracks the satellite in a telescope, stewing the telescope to follow the satellite as it moves across the sky, recording light generated by the satellite with a light sensor such as a video camera. The datastream is regenerated through analysis of recorded video. Satellite downlink is initiated by detection of eclipse, by command via radio uplink, or in response to a periodic automatic timer. In an alternative embodiment, the satellite represents the datastream through modulation of its effective albedo or reflective flux during periods of solar illumination.

Abstract: Free space optical communication systems, methods, and apparatuses are provided. A system embodiment includes a photodetector for receiving a beacon signal transmitted from a ground communication apparatus, a light source for emitting a light beam toward a source of the beacon signal, where the light beam includes a signal to be transmitted, and a high speed tracking actuator coupled to the light source for moving the light source to maintain the light beam in a direction toward the source of the beacon signal transmitted from the ground communication apparatus.

Abstract: A system for transmission of information between at least two players in a training area comprises means on a first (1) of said players for encoding light pulses and means for transmitting information in the form of such coded light pulses towards at least one second (2-4) of said players, said second player having means for receiving said light pulses and means for decoding the information thereof. Each of said players is provided with a clock, and the system comprises means for keeping said clocks synchronized. The encoding means and the decoding means are adapted to utilize data of times of transmission and receipt of said light pulses for transmitting information from the first player to the second player.

Abstract: A hybrid communications link includes a slow, reliable communications link and a fast unreliable communications link. Communication via the hybrid communications link selectively uses both the slow, reliable communications link and the fast, unreliable communications link.

Abstract: This invention pertains to optical fiber transmission networks, and is particularly relevant to transmission of high volume of data and voice traffic among different locations. In particular, the improvement teaches improvements to an optical transport system to allow for efficient and flexible network evolution.

Abstract: A high-speed optical communications cell is integrated at the interior of a two-dimensional imaging array. The combined receiver and imager carries out both photodetection (converting photons to electrons) and circuit functions (e.g. amplifying and integrating the signals from the photodetectors). The high-speed receiver cell comprises a photodetector and a high-speed amplification circuit, providing an electrical output which can follow a rapidly varying optical signal falling on the photodetector. The imaging array comprises an array of photodetectors and readout circuits, providing an electrical representation of the variation of light with position across the receiver surface. The presence of an imaging array surrounding the communications receiver, and in the same plane as it, allows a single optical path to be used for source acquisition and tracking as well as for data reception.

Abstract: A laser communications and position location system has a laser transmitter with a laser array radiating modulated laser beams upward at convergence angles that determine altitude of a free space junction where the beams converge. The free space junction scatters the modulated laser beams and a laser receiver receives the scattered modulated laser beam light and recovers the data. A modulator modulates the laser array with data. The laser transmitter may include a data link to transmit the free space junction position to the laser receiver to aid in finding it. The laser receiver has an optical detector with an adjustable field of view and gain to minimize background light noise and to demodulate the received modulated scattered laser beams. The laser receiver determines a precise location of the laser transmitter upon finding the free space junction.

Abstract: A system and method of free-space optical satellite communications includes a ground station and transceiver for transmitting and receiving an optical communications signal. Adaptive optics at the ground station are operative with the transceiver for determining the shape of any distortions in the wavefront of the optical communications signal and compensating at the ground station for the distortions. A satellite includes a transceiver for transmitting and receiving the optical communications signal and includes adaptive optics for determining the shape of any distortions in the waveform of the optical communications signal and compensating at the satellite for the distortions.

Abstract: A communications system for wireless transceiving of information, comprising at least one multiple optical beam scanning array transceiver located in a satellite for wirelessly transceiving the information; and at least two terminals at diverse locations capable of wirelessly transceiving the information between the terminals and the satellite, and an apparatus for determining atmospheric conditions for use in adjusting the multiple beam scanning array transceiver parameters.

Abstract: A first node (205) in a network includes a non-optical transceiver (415) and an optical subsystem (410). The non-optical transceiver (415) sends a request message to establish an optical link from the first node (205) to a second node via electrical signals over an electrically transmissive medium. The optical subsystem (410) establishes an optical link between the first node and the second node based on the receipt of the request granted message and transmits data between the first node and the second node via optical signals over the optical link.

Abstract: A satellite constellation has a plurality of network satellites that form a network. A gateway satellite is disposed adjacent to the network. The gateway satellites receive an optical signal from the network and converts the signal to an electrical signal. The gateway satellite has a sorter and a reshaping circuit for reshaping the electrical signal to form a reshaped signal. The electrical signal is converted back to an optical signal corresponding to the reshaped signal. The optical signal corresponding to the reshaped signal has reduced noise in comparison to the input optical signal. The optical signal is then retransmitted to another satellite.

Abstract: In an adaptive optics module, wavefront sensing and data detection are implemented in a single device. For example, an optical-to-electrical converter converts a data-encoded optical beam to an intermediate electrical signal, which contains both the data encoded in the beam and also wavefront information about the beam. The data and wavefront information are later separated, for example by frequency filtering.

Abstract: A system and method for providing real-time imaging for use in wide area space based surveillance utilizing an Optical Tera-bps Satellite (OPTSAT) network, including a plurality of OPTSATs, wherein an object is imaged with at least one surveillance aperture operatively linked to at least one of the plurality of OPTSATs is disclosed herein. The optical image data obtained the at least one surveillance aperture is processed in a one image processor, and displayed in a terminal capable of wirelessly transceiving information with the plurality of OPTSATs.

Abstract: A communications system for wireless transceiving of information, comprising an optical array subsystem for transceiving optical signals and a millimeter wave subsystem for transceiving millimeter wave signals, and a beam steering controller for controlling the direction of the optical and millimeter wave signals. The communication system may be on a flying platform, such as a satellite and may communicate with multiple remote terminals.