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 {range: 1-10}.
PASSES n:	Set number of passes {n=1: causal, n=2: zero-phase}.
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.:

SAC> HIGHPASS NPOLES 4 CORNER 2

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

SAC> 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)