darpsd(1)

PROGRAM
darpsd - 1D Autoregressive (AR) PSD

SYNTAX

darpsd

-i  input file (xviff file)

-o  resulting output file (xviff file)

[-n]
    number of points for PSD estimate

[-t]
    AR coefficients from Lattice filter(1) or TAPPED filter(0) (default)

[-p]
    Phase estimate(0) or PSD estimate(1) (default)

[-y]
    do NOT normalize (0) or YES normalize(1) (default)

[-d]
    down vectors(0) or across bands(1) (default)

[-V]
    Gives the version for darpsd

[-U]
    Gives the usage for darpsd

[-P]
    Prompts for command line options

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

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

DESCRIPTION
darpsd 1D AR PSD/Phase Estimation. Determines the 1D autoregressive (AR) PSD and Phase spectral estimate of the input file. The input file consists of autoregressive parameters. The autoregressive parameters can originate either on a tapped-delay or lattice filter realizations. The user is allowed to extrapolate the PSD or Phase estimate to the desired number of points. It can operate on Real and Complex data.

NOTE 1: complex data is expected to be in rectangular (not polar) form.

NOTE 2: if input data is real the Phase spectra will be 0.0.

For a more theoretical discussion of AR PSD estimation algorithms see: Modern Spectral Estimation: Theory and Application, by Steven M. Kay, Prentice Hall, 1988.

darpsd does not work on explicit location data and will return an error when such a file is encountered. No output file will be created. darpsd 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 direction of processing can be changed so that each band is processed 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

-n  type: integer
    desc: number of points for PSD estimate
    default: 1
    bounds: value > 0

-t  type: boolean
    desc: AR coefficients from Lattice filter(1) or TAPPED filter(0) (default)
    default: false

-p  type: boolean
    desc: Phase estimate(0) or PSD estimate(1) (default)
    default: true

-y  type: boolean
    desc: do NOT normalize (0) or YES normalize(1) (default)
    default: true

-d  type: boolean
    desc: down vectors(0) or across bands(1) (default)
    default: true

EXAMPLES

SEE ALSO
intro(1), verror(3), vgparms(3), vutils(3), ldarpsd(3)

RESTRICTIONS
works only on VFF_TYP_COMPLEX and VFF_TYP_FLOAT.

darpsd 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.