Causal Instrument Corrections for Short-Period and Broadband
Seismometers  Document Type   Publication Date    Of all the
filters applied to recordings of seismic waves, which include
source, path, and site effects, the one we know most precisely
is the instrument filter. Therefore, it behooves seismologists
to accurately remove the effect of the instrument from raw
seismograms. Applying instrument corrections allows analysis of
the seismogram in terms of physical units (e.g., displacement or
particle velocity of the Earth’s surface) instead of the output
of the instrument (e.g., digital counts). The instrument
correction can be considered the most fundamental processing
step in seismology since it relates the raw data to an
observable quantity of interest to seismologists. Complicating
matters is the fact that, in practice, the term “instrument
correction” refers to more than simply the seismometer. The
instrument correction compensates for the complete recording
system including the seismometer, telemetry,