MULTI-ACCESS FREE-SPACE LASER COMMUNICATION SYSTEM DESIGN

MULTI-ACCESS SPACE OPTICAL COMMUNICATION SYSTEM DESIGNS ARE IMPLEMENTED THAT RESULT IN SMALL-SIZE, LIGHT-WEIGHT TERMINALS ON BOARD GEO AND LEO SATELLITES. SYSTEM DESIGNS ARE PROVIDED INCORPORATING THE ADVANCING HIGH-POWER, COHERENT GALLIUM ALUMINUM ARSENIDE LASER DIODES AND DIODE ARRAY TECHNOLOGY RESULTING IN SIMPLER, LOWER-COST SYSTEMS INCORPORATING GIMBAL-ONLY TRACKING AND DIRECT DETECTION. LASER TRANSMITTERS DESIGNS ARE PROVIDED WHICH PERMIT DATA RATES IN THE 1 MBPS REGIME TO BE TRANSMITTED FROM EACH LEO TO THE GEO USING MULTI-WATT LASER DIODES WITH EFFICIENCIES UP TO 50%. IN ADDITION, SYSTEM DESIGNS ARE PROVIDED THAT ENABLE SIMULTANEOUS DATA TRANSMISSION FROM A NUMBER OF LEO SATELLITES TO GEO. SYSTEM CONCEPT DESIGNS FOR LEO AND GEO LIGHT-WEIGHT TERMINALS INCORPORATING ACQUISITION, TRACKING, AND COMMUNICATION ARE GIVEN. MULTI-ACCESS APPROACHES FOR THE GEO SATELLITE INCLUDE ONE LARGE-APERTURE, WIDE-FIELD-OF-VIEW GIMBALLED SYSTEM TERMINAL, OR ALTERNATIVELY, A NUMBER OF SMALL-APERTURE (2 INCH) INDEPENDENTLY GIMBALLED TERMINALS. LEO TERMINALS USE 2 INCHAPERTURES AND WEIGH THIRTY POUNDS. SYSTEM AND COMPONENT SPECIFICATIONS ARE GIVEN FOR THE SELECTED CONCEPT, AND A RISK ASSESSMENT IS PROVIDED FOR A BALANCED DESIGN.