decimate

This decimates seismograms by the given factor or to the given sample rate. Any needed low pass filtering can be done before applying this or using the antiAliasFilter element to avoid aliasing. The antiAliasFilter is the same as the oregonDSPFilter ingredient, with the passband and highFreqCorner determined automatically. If the seismogram sample rate is not an integer multiple of the desired max sample rate, then the resulting sample rate will be less than or equal to the desired. For example if the seismogram is 100 samples per second and the desired rate is 30 sps, then the decimation factor will be 4 and the resulting rate will be 25 sps. Previous versions of SOD allow a naked integer factor in this, now you must use either maxSamplesPerSec or byFactor subelements.

Example

<decimate>
    <maxSamplesPerSec>10</maxSamplesPerSec>
</decimate>

This consists of

<decimate>

interleave
choice
<maxSamplesPerSec>float</maxSamplesPerSec>
<byFactor>Token</byFactor>

<antiAliasFilter> optional
interleave
optional choice
<butterworth/>
<chebyshevI/>
<chebyshevII/>

<numPoles>integer</numPoles> optional
<filterType> optional
choice
NONCAUSAL
CAUSAL
TWOPASS

</filterType>
<epsilon>float</epsilon> optional
</antiAliasFilter>
</decimate>

Places this can be found

In seismogramProcess there is a choice between all of the following