SAC (Seismic Analysis Code) is a general purpose interactive program designed for the study of sequential signals, especially timeseries data. Emphasis has been placed on analysis tools used by research seismologists in the detailed study of seismic events. Analysis capabilities include general arithmetic operations, Fourier transforms, three spectral estimation techniques, IIR and FIR filtering, signal stacking, decimation, interpolation, correlation, and seismic phase picking. SAC also contains an extensive graphics capability.

The IRIS DMC distributes SAC software for scientists conducting research using IRIS data. Please fill out the online form to request a copy of the SAC software.

Learn more about SAC

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2008/09/04 Version 101.2

• Supported Platforms: Solaris, Linux (32/64 bit) Mac OS X
  (PPC and i686, <= 10.5), and Windows under Cygwin.
• See Compliation notes for Version 101.1
• Multiple-session command-line history file (See
  sac/utils/README_utils)
• (Re)-introduction of SAC Library
  • Filtering, Envelopes, Correlations, Convolutions
  • Examples in sac/doc/examples
  • sac-config helper script for compiling (sac/bin/sac-config)
  • More to come in future releases
• Update: Evalresp now at 3.2.40
• BUG FIX: ASCII to Integer Conversion
• BUG FIX: Scripts which do not end with a quit
• BUG FIX: Transfer command output cleaned up
• BUG FIX: Fixed Conversion of Real floating point numbers to text
• BUG FIX: Interpolation of long time series fixed
• BUG FIX: Get Blackboard variable (getbbv)
• Enhancement: Matlab scripts to read and write SAC Files
• Enhancement: Added rsach to read a SAC Header
• Enhancement: Added readcor to read a Correlation Function
• Enhancement: Matlab/SAC Interaction available through configure
• Enhancement: lh columns 2 can now be set in an initializing macro
• Enhancement: GMT Map command updated
• Enhancement: SAC now knows if it run from a script “<
• Updated build system, now cleaner using config.h

Known Bugs

• SSS traveltimes command (endian issue)
• do file wild segmentation fault with a large number of files
• plot header is incorrect
• reading of long integers done incorrectly
• ch o gmt does not report errors
• line termination does not handle all type of line termination
• merge command broken
• time shrinks on plots with large number of records
• SGF byte order
• errors should be on stdout
• Scaling, Limit on files is currently 1000

2008/10/28 Patches for critical bug fixes (not for enhancements)

001: Reliability Fix: October 2008

• Buffer Overflow in History
• Patch File: 001_history_buffer.patch
• A possible buffer overflow found in the history extension was found. It could cause sac to behave in an unstable fashion

002: Reliability Fix: October 2008

• Closing X11 Plotting Window
• Patch File: 002_close_window.patch
• Closing the X11 Plotting window caused sac to crash. This patch disables the close window option.

003: Reliability Fix: October 2008

• SeisMgr Database Flag
• Patch File: 003_use_database.patch
• There was a bug in the option to turn on and off the SeisMgr Database

This patch fixes the option and leaves the SeisMgr Database on by default. In the sac 101.2 README, “off” was stated as the appropriate default, but the developers now find “on” the better choice. This patch also changes bin/sacinit.csh.in and bin/sacinit.sh.in to say that the default is on.