Robert M. Gagliardi

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Consideration is presently being given to an 'optical-RF relay deep space communication link that transmits optical PPM data . from spacecraft to orbital relay, then retransmits the data via microwave to ground. It is generally advantageous to use Reed-Solomon (RS) encoding over the PPM optical link for improved error correction. In this paper several(More)
A bstraet-Agile frequency synthesizers are the common device used for commandable, wide-band frequency hopping in frequency-hopped (FH) communications. When the design of such synthesizers involve divide-down phase lock loops, transients exist that limit the ability of the loop to bop rapidly. These transients lead to effective energy loss that degrades(More)
This paper describes and analyzes two types of laser system employing active transponders that could accurately determine Doppler and range to deep space vehicles from earth-orbiting satellites. The first is a noncoherent optical system in which the Doppler effect on an intensity-modulating subcarrier is measured. The second is a coherent optical system in(More)