
dmusic(1)                    Khoros                     dmusic(1)

PROGRAM
     dmusic - 1D MUSIC Spectral Estimation

SYNTAX
     dmusic

     -i             input file (xviff file)

     -o             resulting output file (xviff file)

     [-s]           model order (same as number of eigenvectors)

     [-f]           specify number of spectral values desired

     [-p]           do not center the psd estimate (0) or center
                    the psd estimate (1)

     [-j]           scalar processing (0) or vector processing
                    (1)

     [-d]           data processing direction (0 = down vectors,
                    1 = across bands)

     [-g]           type of autocorrelation file to be used:
                    0 (choose biased autocorrelation estimate),
                    1 (choose unbiased autocorrelation estimate),
                    or 2 (choose FFT based autocorrelation esti-
                    mate)
                       [default = 0]

     [-c]           Use AIC (0) or MDL(1) criterion
                                        -OR-

     [-k]           dimension of noise subspace sequence

     [-V]           Gives the version for dmusic

     [-U]           Gives the usage for dmusic

     [-P]           Prompts for command line options

     [-A [file1]]   Creates the answer file called dmusic.ans or
                    file1

     [-a [file1]]   Uses dmusic.ans or file1 as the answer file

DESCRIPTION
     An implementation of the MUSIC (Multiple Signal Classifica-
     tion) for spectral estimation.  MUSIC is a spectral estima-
     tion technique based on eigendecomposition of the autocorre-
     lation matrix of a sampled random process.

     The process involves generating estimates of the eigenvalues
     and eigenvectors of a Toelitz and Hermitian autocorrelation
     matrix estimate.  The eigenvectors are then sorted by
     ascending order of their corresponding eigenvalues.  The
     eigenvectors corresponding to the k smallest, approximately
     equal eigenvalues are selected.  k is the dimension of the
     noise subspace, and can be specified by the user or may be
     computed using the Akaike (AIC) or Minimum Description
     Length (MDL) information theoretic criteria.

     k power spectrum estimates corresponding to the k selected
     eigenvectors are computed and averaged to form the MUSIC
     power spectrum estimate.

     For a more theoretical discussion of the MUSIC algorithm
     see:  Optimum Signal Processing by Sophocles Orfranidis,
     McGraw-Hill, 1988; or Eigenvector-Based Parametric Modeling
     of Time-Domain Signals:  Application to Nuclear Magnetic
     Resonance Spectroscopy by Glen Abousleman (Master's thesis,
     University of New Mexico, Dept. of EECE, 1990).

     dmusic does not work on explicit location data and will
     return an error when such a file is encountered.  No output
     file will be created.  dmusic works only on VFF_TYP_FLOAT or
     VFF_TYP_COMPLEX data files.

     Input/Output Files
     The input file must be of type VFF_TYP_FLOAT or
     VFF_TYP_COMPLEX.  The output file returned will be of size
     specified by the user.  If the data is of type
     VFF_TYP_COMPLEX and complex aithmetic is selected then the
     output file will be of type VFF_TYP_FLOAT.
     *********************************************************************

     Process direction
     Data can be processed with either band or vector orientation
     (-d option).  The default data processing direction is in
     the vector direction (-d = 0).  pixel location.  The direc-
     tion of processing can be changed so that each band is pro-
     cessed as a signal (instead of each vector being a signal)
     by setting the -d option to 1.

REQUIRED ARGUMENTS
     -i     type: infile
            desc: input file (xviff file)

     -o     type: outfile
            desc: resulting output file (xviff file)

OPTIONAL ARGUMENTS
     -s     type: integer
            desc: model order (same as number of eigenvectors)
            default: 1
            bounds: value > 0

     -f     type: integer
            desc: specify number of spectral values desired
            default: 1
            bounds: value > 0

     -p     type: boolean
            desc: do not center the psd estimate (0) or center
            the psd estimate (1)
            default: false

     -j     type: boolean
            desc: scalar processing (0) or vector processing (1)
            default: true

     -d     type: boolean
            desc: data processing direction (0 = down vectors, 1
            = across bands)
            default: true

     -g     type: integer
            desc: type of autocorrelation file to be used
            allowed values:
            0 (choose biased autocorrelation estimate),
            1 (choose unbiased autocorrelation estimate),
            or 2 (choose FFT based autocorrelation estimate)

     ***   These arguments are MUTUALLY EXCLUSIVE   ***
      If desired, you may provide ONE AND ONLY ONE of:

     -c     desc: Use AIC (0) or MDL(1) criterion
            default: false

     -k     desc: dimension of noise subspace sequence
            default: 1
            bounds: value >= 0

            ********

EXAMPLES
SEE ALSO
     intro(1), verror(3), vgparms(3), vutils(3), ldmusic(3)

RESTRICTIONS
     works only on VFF_TYP_COMPLEX and VFF_TYP_FLOAT.

     dmusic does not work on explicit location data and will
     return an error when such a data file is encountered.

COPYRIGHT
     Copyright 1992, University of New Mexico.  All rights
     reserved.

Khoros                    Release: 1.0                          1

