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Pointing a ground antenna at a spinning spacecraft using conical scan - Simulation resultsThe results are presented for an investigation of ground antenna pointing errors which are caused by fluctuations of the receiver AGC signal due to thermal noise and a spinning spacecraft. Transient responses and steady-state errors and losses are estimated using models of the digital Conscan (conical scan) loop, the FFT, and antenna characteristics. Simulation results are given for the on-going Voyager mission and for the upcoming Galileo mission, which includes a spinning spacecraft. The simulation predicts a 1 sigma pointing error of 0.5 to 2.0 mdeg for Voyager, assuming an AGC loop SNR of 35 to 30 dB with a scan period varying from 128 to 32 sec, respectively. This prediction is in agreement with the DSS 14 antenna Conscan performance of 1.7 mdeg for 32 sec scans as reported in earlier studies. The simulation of Galileo predicts 1 mdeg error with a 128 sec scan and 4 mdeg with a 32 sec scan under similar AGC conditions.
Document ID
19900065830
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Mileant, Alexander
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Peng, Ted
(JPL Pasadena, CA, United States)
Date Acquired
August 14, 2013
Publication Date
January 1, 1989
Subject Category
Space Communications, Spacecraft Communications, Command And Tracking
Meeting Information
Meeting: IEEE International Conference on Systems Engineering
Location: Dayton, OH
Country: United States
Start Date: August 24, 1989
End Date: August 26, 1989
Sponsors: Wright State Univ., IEEE
Accession Number
90A52885
Distribution Limits
Public
Copyright
Other

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