Accession Number : ADD005357

Title :   Doppler Processing Method and Apparatus.

Descriptive Note : Patent,


Personal Author(s) : Casasent,David Paul

Report Date : 04 Jul 1978

Pagination or Media Count : 10

Abstract : A method and apparatus for determining the value of a Doppler frequency shift component delta f present in a signal f + or - delta f employing a correlation process which utilizes the Mellin transform and is scale invariant. The location of the correlation peak in the reference coordinate system used provides a measure of the magnitude of delta f. The sequence of steps involved in the correlation process when optical apparatus is used include forming a transmittance pattern of the signal f + or - delta f, which has a horizontal scale that is the natural log of the time scale of the original signal, forming a similarly scaled transmittance pattern of the reference signal, f, and utilizing the first pattern in the input plane of a frequency plane correlator that has a holographic matched spatial filter that is produced from the second pattern and contains a term corresponding to the conjugate of the Mellin transform of the reference signal in its frequency plane. (Author)

Descriptors :   *Patents, *Doppler systems, Signal processing, Laser beams

Subject Categories : Lasers and Masers
      Test Facilities, Equipment and Methods

Distribution Statement : APPROVED FOR PUBLIC RELEASE