SAC Command Reference Manual

HIGHPASS

SUMMARY

Applies an IIR highpass filter.

SYNTAX

HIGHPASS {BUTTER|BESSEL|C1|C2},{CORNERS v1 v2},

{NPOLES n},{PASSES n},{TRANBW v},{ATTEN v}

INPUT

BUTTER:Apply a Butterworth filter.
BESSEL:Apply a Bessel filter.
C1:Apply a Chebyshev Type I filter.
C2:Apply a Chebyshev Type II filter.
CORNER v:Set corner frequency to v.
NPOLES n:Set number of poles to n {range: 1-10}.
PASSES n:Set number of passes to n {range: 1-2}.
TRANBW v:Set the Chebyshev attenuation factor to v.
ATTEN v:Set the Chebyshev attenuation factor to v.

DEFAULT VALUES

HIGHPASS BUTTER CORNER 0.2 NPOLES 2 PASSES 1 TRANBW 0.3 ATTEN 30.

DESCRIPTION

See the BANDPASS command for definitions of the filter parameters and descriptions on how to use them.

EXAMPLES

To apply a four-pole Butterworth with a corner at 2 Hz.:

u:  HIGHPASS NPOLES 4 CORNER 2

To apply a two-pole two-pass Bessel with the same corner.:

u:  HP N 2 BE P 2

ERROR MESSAGES

  • 1301: No data files read in.
  • 1306: Illegal operation on unevenly spaced file
  • 1307: Illegal operation on spectral file
  • 1002: Bad value for
    • corner frequency larger than Nyquist frequency.

HEADER CHANGES

DEPMIN, DEPMAX, DEPMEN

SEE COMMANDS

BANDPASS

LATEST REVISION

January 8, 1983 (Version 8.0)