Laser Doppler measurement techniques for spacecraftTwo techniques are proposed for using laser links to measure the relative radial velocity of two spacecraft. The first technique determines the relative radial velocity from a measurement of the two-way Doppler shift on a transponded radio-frequency subcarrier. The subcarrier intensity-modulates reciprocating laser beams. The second technique determines the relative radial velocity from a measurement of the two-way Doppler shift on an optical frequency carrier which is transponded between spacecraft using optical Costas loops. The first technique might be used in conjunction with noncoherent optical communications, while the second technique is compatible with coherent optical communications. The first technique simultaneously exploits the diffraction advantage of laser beams and the maturity of radio-frequency phase-locked loop technology. The second technique exploits both the diffraction advantage of laser beams and the large Doppler effect at optical frequencies. The second technique has the potential for greater accuracy; unfortunately, it is more difficult to implement since it involves optical Costas loops.
Document ID
19870039354
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Kinman, Peter W. (California Institute of Technology Jet Propulsion Laboratory, Pasadena, United States)
Gagliardi, Robert M. (Southern California, University Los Angeles, CA, United States)
Date Acquired
August 13, 2013
Publication Date
January 1, 1986
Subject Category
Space Communications, Spacecraft Communications, Command And Tracking