Abstract:
Exemplary embodiments described herein include a bi-directional Free Space Optical (FSO) communication unit that may be used in a multi-node FSO communication system. The bi-directional FSO unit may include a co-boresighted optical unit such that received and transmitted beams are coincident through a common aperture. Embodiments described herein may be used to correct or accommodate the alignment errors of the received and transmitted beams.
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 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. 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 mirror 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:
The system and method uses free-space optics for telemetry between spacecraft for communication. The system and method uses bright light emitting diodes or other transmitters and a low-light photomultiplier tube or other receiver. Greater transmission distances are possible by using optical bandpass filters and baffles. The system and method are capable of achieving greater distances and data rates with the use of additional transmitters with greater optical power output, including laser diodes.
Abstract:
L'invention vise un système de communication par liaison optique entre un terminal disposé en un point fixe relativement à la surface terrestre, dit "terminal sol" disposant d'un émetteur optique directionnel, et un relais distant, mobile relativement au terminal sol, le terminal sol comportant des moyens d'orientation automatique de l'émetteur optique directionnel en élévation et azimut vers le relais distant, avec une précision compatible avec l'établissement d'une communication optique entre le terminal fixe et le relais distant. Préférentiellement, le terminal sol comporte également des moyens d'alimentation autonome en énergie.
Abstract:
A system for tracking a target includes a dual-band antenna. The dual-band antenna includes a first antenna and a second antenna rigidly coupled to the first antenna. The first antenna is configured to communicate within a first frequency band and the second antenna is configured to communicate within a second frequency band. The system further includes a processing system configured to initialize a pointing direction to point a beam of the first antenna toward the target with a first degree of pointing accuracy, and configured to scan with the first antenna to point the beam of the first antenna more precisely toward the target with a second degree of pointing accuracy.