Abstract: A laser relay module in a free space optical communication network includes: a beacon source for generating an optical beacon signal for aligning a communication channel of a source optical node to a communication channel of a receiving optical node; a beacon inserter for encoding the optical beacon signal with switching information; a telescope for transmitting the encoded optical beacon signal to the receiving optical node; a beacon detector for detecting received switching information from the modulated optical beacon signal, wherein the receiving optical node uses the encoded optical beacon signal to align communication channel of the receiving optical node with communication channel of the source optical node; and a processor for using the detected switching information to change configuration of an optical switch matrix to direct received data to a next optical node in the free space optical communication network.

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: An electro-optical payload for free space optical communication includes: a plurality of optical beam expanders, each for receiving a respective optical signal; an optical cross-connect switch for directing respective optical signals to respective optical output signals; an electrical-to-optical conversion circuit coupled to an input of the optical cross-connect switch for converting an electrical signal to an optical signal for inputting to the optical cross-connect switch; an optical-to-electrical conversion circuit for converting an optical signal output from the optical cross-connect switch to an electrical signal; and an electrical regeneration circuit including a second optical-to-electrical conversion circuit coupled to an output of the optical cross-connect switch and a second electrical-to-optical conversion circuit coupled to an input of the optical cross-connect switch for converting an optical out signal of the optical cross-connect switch to an electrical signal.

Abstract: A laser relay module in a free space optical communication network includes: a beacon source for generating an optical beacon signal for aligning a communication channel of a source optical node to a communication channel of a receiving optical node; a beacon inserter for encoding the optical beacon signal with switching information; a telescope for transmitting the encoded optical beacon signal to the receiving optical node; a beacon detector for detecting received switching information from the modulated optical beacon signal, wherein the receiving optical node uses the encoded optical beacon signal to align communication channel of the receiving optical node with communication channel of the source optical node; and a processor for using the detected switching information to change configuration of an optical switch matrix to direct received data to a next optical node in the free space optical communication network.

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 more than three (N) angles-only observations according to an error metric. The search is conducted by solving a boundary-value 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. 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: An electro-optical payload for free space optical communication includes: a plurality of optical beam expanders, each for receiving a respective optical signal of incoming optical signals; an optical cross-connect switch for directing respective optical input signals to respective optical output signals; an electrical-to-optical conversion circuit coupled to an input of the optical cross-connect switch for converting an electrical signal to an optical signal for inputting to the optical cross-connect switch; an optical-to-electrical conversion circuit coupled to an output of the optical cross-connect switch for converting an optical signal output from the optical cross-connect switch to an electrical signal; and an electrical regeneration circuit including a second optical-to-electrical conversion circuit coupled to an output of the optical cross-connect switch and a second electrical-to-optical conversion circuit coupled to an input of the optical cross-connect switch for converting an optical out signal of

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 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 laser relay module for free space optical communications including an optical telescope for receiving and transmitting optical beams; an optical diplexer for separating transmitting and received optical beams; an optical amplifier; a modulated beacon laser for line of sight control of a plurality of communicating remote network nodes; a beacon beam detector for detecting an incoming beacon optical beam for line of sight control of the optical telescope and receiving data from other network nodes; and means for inserting an output of the modulated beacon laser into the optical telescope for transmission to another network node, and for transporting the incoming beacon optical beam to the beacon detector.

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: 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 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: 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 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: A multi-directional sensor system includes a light source configured to generate a beam of electromagnetic radiation; and a transmitter configured to transmit the beam of electromagnetic radiation to a target. The transmitter may include (i) a plurality of optical fibers, wherein one or more of the optical fibers are configured to receive the beam of electromagnetic radiation, and (ii) a surface on which one end of each of the plurality of optical fibers terminate in a different direction and/or orientation thereof to emit electromagnetic radiation. A detector is configured to detect electromagnetic radiation responsive to electromagnetic radiation transmitted to the target. A method of sensing is also disclosed.

Abstract: A multi-directional sensor system includes a light source configured to generate a beam of electromagnetic radiation; and a transmitter configured to transmit the beam of electromagnetic radiation to a target. The transmitter may include (i) a plurality of optical fibers, wherein one or more of the optical fibers are configured to receive the beam of electromagnetic radiation, and (ii) a surface on which one end of each of the plurality of optical fibers terminate in a different direction and/or orientation thereof to emit electromagnetic radiation. A detector is configured to detect electromagnetic radiation responsive to electromagnetic radiation transmitted to the target. A method of sensing is also disclosed.