Spectral dmc 6 software#

Large amplitude acausal spikes are recorded on this channel while the mass is against its stops:Д®xample of a mass drifting between stops in trace view. This behavior may have coincided with a mass recenter attempt, but itвЂ™s unconfirmed. This horizontal component began showing long period noise and drift followed by an episode of bouncing between both stops. The trace below shows the pegging of a Guralp CMG-3T borehole mass recorded on a Q330:Д®xample of a CMG-3T mass drifting against its stop in trace view. The corresponding PSD shows that energy near 80 seconds never falls below a certain level, even when the rest of the pass band is quiet: The trace below, which has been low-pass filtered below 1 second, illustrates this:Д®xample of harmonic ringing in trace view. The STS-2 at PASC is ringing at 80 seconds for some unknown reason. Than do gaps with smaller amplitude offsets:Д®xample of a gap with a small amplitude difference in trace view.Д®xample of a gap with a small amplitude difference in PSD view.

Have larger intercepts (lie farther above the noise model curves):Д®xample of a gap with a large amplitude difference in PSD view. Gaps with larger amplitude offsets:Д®xample of a gap with a large amplitude difference in trace view. The lineвЂ™s intercept depends on the amplitude difference across the gap. The trace shows the large (~7000 count) long-period noise levels during the warm hours:Д®xample of diurnal noise when noisy in trace view.Д®xample of a local earthquake in trace view.Д®xample of a local earthquake in PSD view.Д®xample of a teleseismic earthquake in trace view.Д®xample of a teleseismic earthquake in PSD view.ДЄ data gap maps as a line in a PSD plot with a slope of about 20 dB per decade. The next PSD below shows the SRU during its noisier times:ДЄll curves for this PSD represent local day time:Д®xample of noisy time periods associated with diurnal noise. The trace shows night time background noise levels of ~300 counts:Д®xample of diurnal noise when quiet in trace view. The bars below show time of day corresponding to the PSD. The PSD below shows the SRU during its quieter times:Д®xample of diurnal noise when quiet in PSD view. SRU resides in a near-surface vault and shows long period diurnal thermal noise during daylight hours (~14:00-02:00 UTC). The response is similar to a channel mass resting against the stops.Д«ack to features list Diurnal Thermal Noise The PSD reflects that the amplitudes are only a few counts and vary from sample to sample: The PSD for this quiet site shows low power, even at long periods on horizontal channels:Д®xample of normal background noise in PSD view.ДЇor a few days, the sensor at RLMT went out and the station recorded digitizer noise:Д®xample of digitizer noise in trace view.

ISCO is an example of a quiet site in a cave with minimal background noise: The Peterson new high and low noise model curves are displayed on the PSD plots for reference (grey lines).ДЄt the end of the article is a Self Quiz showing each PSD so you can try naming the waveform that generated it.

Spectral dmc 6 software#

The figures shown here (from the pqlx software developed by Richard Boaz) include: ItвЂ™s intended to serve as a growing reference for interpreting PSDs. This article is a small compendium of waveform features:ДЄnd their expression in power spectral density ( PSD) plots.