Data
Recording
Acoustic and seismic data are
recorded to stand-alone data loggers deployed out on the
volcano or via radio telemetry to an observatory where data is archived
on a computer and sometimes output to a helicorder (or paper
record). Data recorded to stand-alone
digitizers are often of very high quality, because these digitizers, like the one
below (Reftek 130), which was lent out by IRIS PASSCAL, has 22.5 effective
bits of resolution. This means
that voltage inputs as low as 3 microVolts and as high as 10 Volts
stay on scale. These devices also
record with high-accuracy GPS time stamping, which is necessary
for most applications in seismology. A
drawback to stand-alone installations is that data need to be
manually retrieved, downloaded, and converted to viewable
files. Most of the data showcased in this powerpoint was collected with high fidelity
stand-alone digitizers.
