Accession Number : AD0758851

Title :   Transformation of the Spectrum of a Signal in Communication Between Relativistically Moving Inertial Frames,

Corporate Author : CALIFORNIA UNIV BERKELEY SPACE SCIENCES LAB

Personal Author(s) : Morgan,Michael A. ; Silver,Samuel

Report Date : MAR 1973

Pagination or Media Count : 47

Abstract : Future space exploration may involve communications between space craft moving at relativistic velocities. One of the significant problems associated with such communication is spectral distortion of signals which are propagated between relativistic frames. This distortion is generated by both changing propagation distances and purely relativistic electromagneric filed transformations. In the paper a linear integral transformation is formulated for relating the Fourier spectra of the source antenna excitation current and the resulting incident electric field at the receiving antenna. The kernel of the transformation is evaluated for the case of a steerable source antenna tracking on the advanced receiver position. The transformation is then applied to the case of an ideal thin-wire half-wave dipole source antenna excited by a narrow-band D.S.B. modulated current. The specific distortions of spectral spreading and translation are then related to increased bandwidth and upper cutoff frequency requirements of receiving systems in relativistic applications. (Author)

Descriptors :   (*SPACE COMMUNICATIONS, *RELATIVITY THEORY), (*ANTENNA RADIATION PATTERNS, DISTORTION), (*RADIO TRANSMISSION, RELATIVITY THEORY), TRANSMITTER RECEIVERS, DOPPLER EFFECT, GAIN, POWER SPECTRA, INTEGRAL TRANSFORMS, FOURIER ANALYSIS, BESSEL FUNCTIONS, DIPOLE ANTENNAS, CURVE FITTING, GRAPHICS

Subject Categories : Radiofrequency Wave Propagation
      Radio Communications

Distribution Statement : APPROVED FOR PUBLIC RELEASE