SUMMARY

Applies a Benioff filter to the data.

SYNTAX

BENIOFF

DESCRIPTION

This command is a digital approximation used to emulate the response of a short-period seismograph which was used by a VELA Program started by the U. S. Air Force about 1960. This Long Range Seismic Measurements (LRSM) program used truck vans and trailers to deploy moveable seismic systems, principally in North America, to record controlled source seismic experiments. Most of the seismic profiles were radial lines or circular arcs about the Nevada Test Site (NTS). Two semi-permanent sites or installations were Kanab, UT, and Mina, NV.

LLNL continued operation of KN-UT and MI-NV after the LRSM program. These two stations used a variable-reluctance short-period seismometer (with a natural frequency of 1 Hz, critically damped) which was designed and named after Professor Hugo Benioff of Cal Tech. This short-period seismometer was coupled to a galvanometer (with a natural frequency of 5 Hz and damped to 0.9 critical). The coupling factor was nominally defined at 0.01 (or loosely coupled at low magnification settings which were used for recording the larger explosions) and the response was nearly flat-to-velocity between 1 and 5 Hz. When LLNL converted this system to a broadband, flat-to-velocity telemetered system, an analog filter was designed to shape a passband into the LRSM short-period passband. This command executes a digital equivalent of that analog shaping filter which produces an output (measured in nanometers) analogous to the LRSM short-period system.

HEADER CHANGES

DEPMIN, DEPMAX, DEPMEN

LATEST REVISION

May 15, 1987 (Version 10.2)